From Wikipedia, the free encyclopedia
Alphabetical listing of underwater diving related topics
See the
Glossary of underwater diving terminology for definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
See the
Outline of underwater diving for a hierararchical listing of underwater diving related articles
See the
Index of underwater divers for an alphabetical listing of articles about underwater divers
See the
Index of recreational dive sites for an alphabetical listing of articles about places which are recreational dive sites
The following
index is provided as an overview of and topical guide to underwater diving:
Surface-supplied divers riding a stage to the underwater workplace
Underwater diving can be described as all of the following:
A
human activity – intentional, purposive, conscious and subjectively meaningful sequence of actions. Underwater diving is practiced as part of an occupation, or for recreation, where the practitioner submerges below the surface of the water or other liquid for a period which may range between seconds to order of a day at a time, either exposed to the ambient pressure or isolated by a pressure resistant suit, to interact with the underwater environment for pleasure, competitive sport, or as a means to reach a work site for profit or in the pursuit of knowledge, and may use no equipment at all, or a wide range of equipment which may include breathing apparatus, environmental protective clothing, aids to vision, communication, propulsion, maneuverability, buoyancy and safety equipment, and tools for the task at hand.
1 – 9
A
AAI underwater revolver – Six-round amphibious revolver for naval use
A Blueprint for Survival (cave diving) – Book on cave diving safety by Sheck Exley
ABISMO – Japanese remotely operated underwater vehicle for deep sea exploration
ABLJ – Configuration of diving buoyancy compensator
Acoustic beacon – Device that emits a sound signal to aid location underwater
Acoustic positioning system – System for tracking and navigation of underwater vehicles or divers using acoustic signals
Active addition rebreather – Semi closed circuit rebreather type
Adaptive Support Diver – Scuba diver trained to support divers with disabilities
Administrative controls – Industrial safety
ADS 2000 atmospheric diving system – US Navy armoured diving suit
ADS amphibious rifle – Russian bullpup assault rifle for combat divers
Advanced European Scientific Diver – A diver competent to organise a scientific diving team
Advanced Open Water Diver – Recreational scuba diving certification slightly above minimum entry level
Advanced open-water diver – Recreational scuba diving certification slightly above minimum entry level
Advanced nitrox diver – Technical diving qualification to use multiple mixtures of oxygen enriched air
Advanced SEAL Delivery System – Former Navy SEAL mini-sub deployed from submarines
Advanced trimix diver – Recreational technical diving certification level
Aerosinusitis – Barotrauma of the sinuses
Aerospace Medical Association – Professional organization in aviation, space, hyperbaric and environmental medicine
AIDA Hellas – National representative of AIDA International in Greece
AIDA International (
AIDA ) – Worldwide rule- and record-keeping body for competitive breath-hold events
Air embolism – Vascular blockage by air bubbles
Airlift (dredging device) , also known as air-lift – Dredging device using injected air to move water and entrained load up a pipe
Airlift dredging – Removing underwater sediment using an airlift pump
Air line – Tube or hose carrying a compressed air supply
Air-line diving , also known as airline diving – Basic mode of surface-supplied underwater diving
Airlock , also known as air-lock – Compartment for transfer between environments with different atmospheres
Air lock diving bell – Type of mobile pressure caisson
Air lock diving-bell plant – Underwater work support barge used at Gibraltar
Air spread – The topside base for surface-supplied air diving operations
Air top , also known as air top-up – Modifying or completing a gas blend by adding compressed air
Alert Diver – Quarterly magazine published by DAN
Algal bloom – Spread of planktonic algae in water
Alpazat cave rescue – Six British soldiers trapped in a flooded Mexican cave
Al-Sabehat – Iranian swimmer delivery vehicle
Alternative air source – Emergency supply of breathing gas for an underwater diver
Alternative air supply – Emergency supply of breathing air for an underwater diver
Alternative gas supply – Emergency breathing gas supply
Alternobaric vertigo – Dizziness resulting from unequal pressures in the middle ears
Altitude decompression – Reduction in ambient pressure due to ascent above sea level
Altitude diver – Diver competent to plan decompression at altitude
Altitude Diver – Diver qualification for the skills to decompress at altitude
Altitude diving – Underwater diving at altitudes above 300 m
Aluminaut – First aluminum hulled submarine
Ama (diving) – Japanese pearl divers
Ambient pressure – Pressure of the surrounding medium
American Academy of Underwater Sciences (
AAUS ) – American diving standards organisation
American Canadian Underwater Certifications (
ACUC ) – Recreational diver training and certification agency
American Nitrox Divers International (
ANDI ) – Recreational diver training and certification agency
Amontons' law – Relationship between pressure and temperature of a gas at constant volume
Anchor pattern – Arrangement of anchors allowing precise positioning of a vessel
Anti-fog – Chemicals that prevent the condensation of water as small droplets on a surface
Anti-frogman techniques – Methods of protection from incursions by divers and swimmers
AN/WQX-2 – Diver detection sonar used in defense against underwater incursions
Ankle strap (diving) – Staps worn over the ankles of dry suits to prevent the boots from pulling off when in use
Ankle weights (diving) – Diver trim weights worn at the ankles
ANMP – Association nationale des moniteurs de plongée
ANSTI breathing simulator – Machine to measure work of breathing of diving apparatus
ANSTI machine – Machine to measure work of breathing of diving apparatus
Anti-fog – Chemicals that prevent the condensation of water as small droplets on a surface
Anti-frogman techniques – Methods of protection from incursions by divers and swimmers
Antipodes (submersible) – Commercial submarine built in 1973
Anxiety – Unpleasant state of inner turmoil over anticipated events
AP Diving – British manufacturer of underwater diving equipment
Apeks – British manufacturer of scuba diving equipment
Apnea blackout – Loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive
Apnea finswimming , also known as Apnoea finswimming – Underwater swimming in a swimming pool using mask, monofin and holding one's breath.
Apparent weight – Weight of an object when a force additional to gravity is present
APS underwater rifle – Soviet underwater assault firearm firing unrifled steel flechettes
Aqua Lung America – American company manufacturing recreational diving equipment
Aqua Lung/La Spirotechnique – French company manufacturing breathing apparatus and diving equipment
Aqua-Lung – Original name for open-circuit scuba equipment
Aquanaut – Diver who remains at depth underwater for longer than 24 hours
Aquarium diving – Occupational diving in large aquariums
Aquascope – Underwater viewing device
Aquathlon (underwater wrestling) – Competitive underwater wrestling
Aqueon – Diver powered propulsion device
Archaeological diving – Method in underwater archaeology
Archaeology of shipwrecks – Study of human activity through the analysis of shipwreck artifacts
Archimède – French Navy bathyscaphe
Argox – Gas mixture occasionally used by scuba divers for dry-suit inflation
Archimedes' principle – Buoyancy principle in fluid dynamics
Army engineer diver – Armed forces occupation
Army Ranger Wing – Special operations force of the Irish Defence Forces
Artificial gills (human) – Hypothetical devices to extract oxygen from water
Artificial reef – Human-made underwater structure that functions as a reef
Artificial Reef Society of British Columbia (
ARSBC ) – Canadian non-profit to create artificial reefs for habitat enhancement and recreation
AR vest – Type of jacket harness for surface-supplied diving
Ascending and descending (diving) – Procedures for safe ascent and descent in underwater diving
Ascent and descent (diving) – Procedures for safe ascent and descent in underwater diving
Ascent blackout – Loss of consciousness caused by cerebral hypoxia on ascending from a deep freedive
Ascents and descents (diving) – Procedures for safe ascent and descent in underwater diving
Ascent to altitude after diving – A type of extended decompression
Asphyxia – Severely deficient supply of oxygen
Assisted ascent – An emergency ascent during which the diver is provided with breathing gas by another diver
Association nationale des moniteurs de plongée – French recreational diver training and certification agency
Association of Diving Contractors International (
ADCI ) – Non-profit organization for promoting standards and knowledge for commercial diving
Atlantis ROV Team – High-school underwater robotics team from Whidbey Island, Washington, United States
Atmospheric diving suit – Articulated pressure resistant anthropomorphic housing for an underwater diver
ASM-DT amphibious rifle – Russian folding stock underwater firearm
Association nationale des moniteurs de plongée (
ANMP ) – French recreational diver training and certification agency
Atmospheric diving suit – Articulated pressure resistant anthropomorphic housing for an underwater diver
Atmospheric diving system – Diving equiment that isolates the diver from ambient pressure
Atmospheric pressure diving – Articulated pressure resistant housing for underwater diver
Atmospheric suit diving – Diving in an articulated pressure resistant anthropomorphic housing
Atmospheric pressure – Static pressure exerted by the weight of the atmosphere
Atrial septal defect – Human heart defect present at birth
Attitude (diver) – Alignment of the priciple axes of a diver in the water
Australian Diver Accreditation Scheme (
ADAS ) – Australian based international occupational diver accreditation organisation
Australian Submarine Rescue Vehicle Remora – Diving bell operated by the Australian Navy
Australian Underwater Federation (
AUF ) – Governing body for underwater sports in Australia
Auto-dump valve – Valve to release excess gas from a dry suit
Automatic diluent valve – Demand valve to maintain volume of a rebreather loop
Autonomous diver , also known as Autonomous Diver or Autonomous scuba diver – International minimum standard for entry level recreational scuba diver certification
Autonomous Robotics Ltd – UK company developing an autonomous underwater vehicle
Autonomous underwater vehicle – Uncrewed underwater vehicle with autonomous guidance system
AUV-150 – Unmanned underwater vehicle in development in by Central Mechanical Engineering Research Institute
AUV Abyss – Autonomous underwater vehicle for mapping of the seabed and water column data collection
Avascular necrosis – Death of bone tissue due to interruption of the blood supply
B
Bachrach, Arthur J. – American psychologist and administrator (1923–2011)
Back gas – Scuba breathing gas carried on the back of the diver
Back kick (finning) – Finning technique to move backwards
Back-mounted scuba – Scuba set carried on the diver's back
Backplate and wing – Type of back-mount scuba harness
Bail out to open circuit – Abort a rebreather dive and surface using open circuit scuba
Bail-out cylinder – Emergency gas supply cylinder carried by a diver
Bailout (diving) – To switch over to an emergency system during a dive
Bailout block – Valve block on diver's equipment for switching between main and emergency gas supply
Bailout bottle – Emergency gas supply cylinder carried by a diver
Bailout gas – Emergency breathing gas supply carried by the diver
Bailout rebreather – Diving rebreather carried as an emergency gas supply
Bailout set – Emergency gas supply scuba carried by a diver
Bailout system – System to provide emergency breathing gas to a diver
Bailout to open circuit – Abort a rebreather dive and surface using open circuit scuba
Bailout valve – Valve opening the supply of emergency breathing gas
Bailout valve (rebreather) – Valve on rebreather mouthpiece to switch to emergency gas supply
Baited remote underwater video – Equipment for estimating fish populations
Band mask – Heavy duty full-face diving mask for surface-supplied diving
Barodontalgia – Tooth pain caused by ambient pressure change
Barostriction – Obstruction of pressure equalization passages
Barotrauma – Injury caused by pressure
Barotrauma of ascent – Injuries caused by a reduction in ambient pressure
Barotraumas of decompression – Injuries caused by a reduction in ambient pressure
Barton, Otis – American diver and actor (1899–1992)
Basic Cave Diving: A Blueprint for Survival – Book on cave diving safety by Sheck Exley
Basic life support – Emergency medical care by first responder
Bathyscaphe – Free-diving self-propelled deep-sea submersible
Beebe, William – American ornithologist, marine biologist, entomologist, and explorer (1877–1962)
Behnke, Albert R. – US Navy physician and diving medicine researcher
Belize Barrier Reef – Series of coral reefs straddling the coast of Belize
Bell bounce diving – Surface oriented diving using a closed bell
Bell cursor – Device to guide and control a diving bell near and above the surface
Bell gas panel – Group of hoses and cables provifing services to a diving bell
Bell harness – Underwater diving safety haeness
Bell stage – Platform below the chamber of a closed diving bell
Bell umbilical – Bundle of hoses and cables providing services to a diving bell
Bell-bounce dive – Surface-oriented diving in a closed bell
Bellman (diver) – Diver working as standby diver and umbilical attendant from a diving bell
Bellman (diving) – The member of a dive team who acts as stand-by diver and tender from the diving bell
Bellows counterlung – Type of rebreather volume compensation component
Benign water – Diving environment with very low risk
Benign water diving – Diving in environments of low risk
Bering Sea Gold – Television series
Bering Sea Gold: Under The Ice – Discovery Channel reality television series
Bert, Paul – French zoologist, physiologist and politician (1833–1886)
Beuchat – French manufacturer of underwater diving equipment
Bifin – Swimfin type with single foot pocket
Biological hazard – Biological material that poses serious risks to the health of living organisms
Black-water (diving) – Oceanic mid-water at night
Black-water diving – Open ocean mid-water diving at night
Blackout of ascent – Loss of consciousness caused by cerebral hypoxia on ascending from a deep freedive
Blood–air barrier – Membrane separating alveolar air from blood in lung capillaries
A Blueprint for Survival (cave diving) – Cave diving safety manual by Sheck Exley
Blauhöhle – Flooded cave system in Southern Germany
Blood shift – Set index article
Blood shift (diving) – Blood flow to the extremities redistributed to the head and torso during a breathhold dive
Blood–air barrier – Membrane separating alveolar air from blood in lung capillaries
Błotniak – One-man wet cabin underwater craft designed in Poland in 1978
Blue Grotto (Malta) – Sea caverns in Malta
Blue hole – Marine cavern or sinkhole, open to the surface, in carbonate bedrock
Blue Hole (New Mexico) – Sinkhole used for scubadiving in New Mexico, United States
Blue Hole (Red Sea) – Submarine sinkhole north of Dahab, Egypt
Blue Lake (Utah) – Large geothermal pond in Utah, U.S.
Blue water diving – Diving in mid-water where the bottom is out of sight
Blue-water (diving) – Oceanic mid-water
Blue-water diving – Underwater diving in oceanic mid-water where the bottom is not visible and is out of diving range
Boarding stirrup – A suspended step to help divers lift themselves from the water into a boat
Boat diving – Procedures specific to diving from boats
Boaty McBoatface – British autonomous underwater vehicle
Bolt snap – Sprung slide gated snap hook
Bond, George F. – US Navy physician and diving medicine and saturation diving researcher
Booster pump – Machine to increase pressure of a fluid
Bottom gas – Gas breathed during the deep part of a dive
Bottom time – The elapsed time of a dive from starting the descent to starting the final ascent to the surface
Bottom timer – An electronic instrument that records depth and elapsed time data on an underwater dive
Boyle, Robert – Anglo-Irish scientist (1627–1691)
Boyle's law – Relation between gas pressure and volume
Bradner, Hugh – American physicist, neoprene wetsuit inventor (1915–2008)
Brazilian commando frogmen – GRUMEC is the special forces unit of the Brazilian Navy
Breaking wave , also known as surf – Wave that becomes unstable as a consequence of excessive steepness
Breath-hold blackout – Loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive
Breathing – Process of moving air in and out of the lungs
Breathing air – Air quality suitable for safe breathing
Breathing air compressor – Machine that compresses atmospheric air at breathing gas quality
Breathing apparatus – Equipment allowing or assisting the user to breath in a hostile environment
Breathing gas – Gas used for human respiration
Breathing gas analysis – Detection and measurement of components of a breathing gas
Breathing gas quality – Purity requirements for gases for human breathing
Breathing gas reclaim system – Equipment to recover helium based breathing gas after use by divers
Breathing gas regulator – Mechanism to control the pressure of a breathing gas
Breathing gas switch – Changing between breathing gasses of different composition while diving
Breathing loop – Breathing gas circuit in a rebreather
Breathing performance of regulators , also known as Breathing regulator performance – Tests of underwater breathing apparatus
Breathing regulator – Mechanism to control the pressure of a breathing gas
Breathing set – Equipment allowing or assisting the user to breath in a hostile environment
Breathing tube (breathing apparatus) – Tube through which to breath ambient pressure air
Briggs Marine – A marine services company based in the United Kingdom
British commando frogmen – Special Boat Service, whose members are drawn largely from the Royal Marines
British Divers Marine Life Rescue – United Kingdom charity organisation
British Freediving Association (
BFA ) – British affiliate to AIDA International
British Octopush Association (
BOA ) – National body for underwater hockey in the United Kingdom
British Sub-Aqua Club (
BSAC ) – Recreational diving club, training and certification agency based in the UK
British Underwater Sports Association (
BUSA ) – British affiliate to the world underwater federation sports committee.
Brubakk, Alf O. – Norwegian decompression researcher (1941–2022)
BRUV – Video system for estimating fish populations
BSAC First Class Diver – Recreational diver competent to lead a group of dives carrying out a project
BSAC London Branch – Original British Sub-Aqua Club branch
Buddy bottle – Alternative name for scuba bailout set
Buddy breathing – Technique for sharing breathing gas from a single mouthpiece
Buddy check – Pre-dive safety checks carried out by two-diver dive teams
Buddy diver – Person diving by the buddy system
Buddy diving – Practice of mutual monitoring and assistance between two divers
Buddy line – A tether between two scuba divers to prevent separation in low visibility
Bühlmann, Albert A. – Swiss physician and decompression researcher (1923–1994)
Bühlmann decompression algorithm , also known as Buhlmann algorithm – Mathematical model of tissue inert gas uptake and release with pressure change
Bühlmann decompression model – Mathematical model of tissue inert gas uptake and release with pressure change
Built-in breathing set – System for supply of breathing gas on demand within a confined space
Built-in breathing system (
BIBS ) – System for supply of breathing gas on demand within a confined space
Built-in breathing system regulator – Hyperbaric chamber breathing regulators that exhaust externally
Buoyancy – Upward force that opposes the weight of an object immersed in fluid
Buoyancy compensator (
BCD ), also known as buoyancy control device – Equipment for controlling the buoyancy of a diver
Buoyancy compensator inflation hose – Inflation gas supply hose on scuba regulator
Buoyancy control (disambiguation)
Buoyancy control in scuba diving , also known as buoyancy control (scuba) – Essential safety skill
Buoyancy control equipment – Diving equipment primarily intended to modify buoyancy of the diver
Buoyant ascent – Type of emergency ascent in diving
Byford Dolphin – Semi-submersible offshore drilling rig
Byford Dolphin diving bell accident – Explosive decompression of an occupied saturation chamber
Burst disc , also known as rupture disc – Non-closing over-pressure relief device
C
Caisson (engineering) – Rigid structure to provide workers with a dry working environment below water level
Cam band , also known as camband, cam strap, or camstrap – Strap with locking buckle to hold scuba cylinder on BCD harness
Canadian Armed Forces Divers – Underwater divers employed by any of the Canadian armed forces
Canister light – Dive light with battery pack and light head connected by cable
Canoe and kayak diving – Recreational diving from a canoe or kayak
Canoe diving – Recreational diving from a canoe
Capernwray Dive Centre – Flooded quarry in Lancashire, England, used as a recreational dive site
Carbon dioxide retention – A tendency to retain abnormally high tissue carbon dioxide levels
Carbon dioxide scrubber – Device which absorbs carbon dioxide from circulated gas
Carbon dioxide scrubbing reaction – Chemical reactions that remove carbon dioxide from air
Carbon monoxide poisoning – Toxic effects of carbon monoxide
Carleton CDBA – Military rebreather by Cobham plc
Carmellan Research – British manufacturer of diving rebreathers
Cascade filling system – Filling pressurized gas from a series of storage cylinders
Cascade storage system – High pressure gas storage system set up for cascade filling
Cave Divers Association of Australia (
CDAA ) – Association to represent cave divers and administrate and support cave diving in Australia
Cave diving – Diving in water-filled caves
Cave Diving Group (
CDG ) – UK based cave diver training and certification agency
Cave diving regions – Geographical distribution of cave diving venues
Cave diving regions of the world – Regions of the world where known cave diving venues exist
Cave line – Line used for navigation in flooded caves
Cave reel – Line holder used to lay and recover guideline in caves
Cavern diver – Certification for diving under a natural overhead within the zone of natural light
Cavern diving – Diving in the part of a cave where the exit is visible by natural light
C-card – Certification as competent to dive to a specified standard
C.E. Heinke & Co. Ltd. – British manufacturer of diving equipment
Cenote – Natural pit or sinkhole that exposes groundwater underneath
Center for Maritime Archaeology and Conservation – Academic centre at Texas A&M University
Central nervous system oxygen toxicity – Adverse effects of exposure to a high partial pressure of oxygen
Cerberus (sonar) – Diver detection device
HMS Challenger K07 – Royal Navy saturation diving support vessel
Chamber operation – Operation of a hyperbaric chamber in support of underwater diving
Chamber operator – A person who operates a diving chamber
Charles's law – Relationship between volume and temperature of a gas at constant pressure
Chase boat – A tender generally not carried by the main vessel
Checklist – Aide-memoire to ensure consistency and completeness in carrying out a task
Chemical hazard – Non-biological hazards of hazardous materials
Christmas tree ladder – Ladder with rungs cantilevered from a central rail
Circular search – A search pattern where the diver swims at a series of distances around a fixed reference point
Circulatory system – Organ system for circulating blood in animals
Cis-Lunar – Manufacturer of electronically controlled closed-circuit rebreathers for scuba diving
Civil liability in recreational diving – Legal duty of care, negligence and liability in recreational diving
Clarke, John R. – American scientist and underwater breathing apparatus authority
Classification of underwater activities – Classification of underwater diving activities by occupational field
Cleaning and disinfection of personal diving equipment – Prevention of infection by shared or contaminated equipment
Clearance diver – Navy diver specialist with explosives
Clearance Divers Life Support Equipment (
CDLSE ) – British military electronically controlled closed circuit rebreather
Clearance diving – Military diving work involving underwater demolition and work with explosives
Clearance Diving Branch (RAN) – Diving unit of the Royal Australian Navy
Clip-on weight – Small weights used to make fine adjustments to a diver's ballast
Closed bell – Hyperbaric chamber for transporting divers vertically through the water
Closed circuit breathing apparatus , also known as closed-circuit breathing apparatus – Apparatus to recycle breathing gas
Closed circuit rebreather set point – Settings for maximum and minimum allowable oxygen partial pressure
Closed circuit scuba – Self contained underwater breathing apparatus which recycles exhaled breathing gas
Closed diving bell – Hyperbaric chamber for transporting divers vertically through the water
Closed circuit bailout – Emergency gas supply from an independent closed circuit rebreather
Closed-circuit oxygen rebreather – Apparatus to recycle breathing gas
Clump weight – A heavy weight suspended on cable used to guide a diving bell
CMAS* scuba diver – Entry level recreational diving certification from CMAS
CMAS** scuba diver , also known as CMAS two-star scuba diver – Autonomous recreational scuba diving certification
CMAS*** scuba diver – Fully trained and experienced recreational dive
CMAS**** scuba diver – A three-star diver with a high level of competence and broad experience
CMAS Europe – Non-profit branch of the world underwater federation representing European affiliates
CMAS Scientific Committee – International organisation for underwater activities
Code of practice – Set of written rules which specifies how people working in a particular occupation should behave
Code of Practice for Scientific Diving: Principles for the Safe Practice of Scientific Diving in Different Environments – Document published by UNESCO
Cold shock response – Physiological response to sudden exposure to cold
Cold-water diving – Underwater diving in water that is cold enough to require special equipment
Comando Raggruppamento Subacquei e Incursori Teseo Tesei – Italian special forces diving unit
Combat Rubber Raiding Craft – Rubberised fabric tactical inflatable boat used by the US Navy
Combat sidestroke – Variation of side-stroke swimming used by United States Navy SEALs
Combined gas law – Combination of Charles', Boyle's and Gay-Lussac's gas laws
Comex therapeutic table CX 30 , also known as
Comex 30 table – A hyperbaric treatment schedule developed by Comex
Comhairle Fo-Thuinn (
CFT ) – Governing body for recreational diving and underwater hockey in Ireland
Commandos Marine – Special operations forces of the French Navy
Commandos Military Unit – Polish special operations unit
Commercial diver registration in South Africa – Registration of commercial divers by the South African Department of Employment andLabour
Commercial diver training – Underwater diving where divers are trained for their work
Commercial diving – Professional diving on industrial projects
Commercial diving school – Place where commercial diving skills are trained and assessed
Commercial offshore diver – Professional diver working offshore
Commercial offshore diving – Professional diving in support of the oil and gas industry
Communications panel – Surface control panel for underwater diving voice communications system
Compagnie maritime d'expertises – French offshore diving contractor
Compass grid search – Technique for finding underwater targets
Compass search – Search patterns controlled by compass directions
Competence (human resources) – Ability of a person to do a job properly
Competitive apnea – Competitive breathhold diving
Competitive freediving – Breathold diving competition disciplines
Competitive spearfishing – Hunting of fish underwater on breath-hold using a hand-loaded spear
Compressed air – Air under a pressure greater than atmospheric
Compression arthralgia – Joint pain caused by fast compression to high ambient pressure
Compressor diving – Crude surface-supplied diving using unregulated air from an industrial low-pressure air compressor
Compressor operator – Person competent to operate a diving air compressor
Concentration – Ratio of part of a mixture to the whole
Concentration gradient – Variation of concentration of a component of a mixture over distance
Confédération Mondiale des Activités Subaquatiques (
CMAS ) – International organisation for underwater activities
Confined water (diving) – A diving environment that is enclosed and bounded sufficiently for safe training
Confined water diving – Diving in water which is enclosed and limited in extent
Conservatism (diving) – Approach to risk reduction for decompression
Constant flow breathing apparatus – Equipment providing a constant flow of breathing gas
Constant flow regulator – Gas pressure control regulator which provides a calibrated output
Constant mass flow regulator – Gas pressure regulator with a constant mass flow delivery
Constant weight apnea – Freediving discipline in which the diver descends and ascends only by swimming, with or without fins
Constant weight bi-fins – Competitive freediving discipline
Constant weight without fins – Freediving discipline
Contaminated water – Water containing high levels of hazardous materials
Continental Shelf Station Two – Undersea research habitat in the Red Sea
Contingency plan – A plan in case something unexpected occurs
Continuous blending and compression – Gas blending by constant flow mixing and analysis
Continuous decompression – Decompression without specific stops at given depths
Continuous flow breathing apparatus – Equipment providing a constant flow of breathing gas
Continuous guide line , also known as continuous guideline – Cord that can lead a scuba diver to open water
Controlled buoyant lift – A technique used by scuba divers to raise an incapacitated diver to the surface
Controlled emergency swimming ascent (
CESA ) – Technique used by scuba divers to return to the surface in an out-of-gas emergency in shallow water
Coral reef – Outcrop of rock in the sea formed by the growth and deposit of stony coral skeletons
Coral Reef Alliance – Non-profit, environmental NGO
Coral reef protection – Modifying human activities to reduce impact on coral reefs.
Corselet (diving helmet) – Part of a diving helmet supported by the shoulders
Cosmos CE2F series – Italian swimmer delivery vehicles
Counterlung – Variable volume component in a rebreather to take up and release gas during a breathing cycle
Cracking pressure – Pressure difference over the diaphragm needed to open a demand valve
Cramp – Pathological, often painful, involuntary muscle contraction
Cressi-Sub – Italian manufacturer of recreational diving and swimming equipment.
Crewed submersible – Small watercraft able to navigate under water
Critical flicker fusion frequency – Concept in the psychophysics of vision
Cross altitude corrections – Adjustments to the US Navy decompression tables to allow for altitude
Cryogenic rebreather – Rebreather that removes CO2 by freezing it out using heat exchange with liquid oxygen
CUMA – Canadian military diving rebreather
Current (hydrology) – Flow of water in a stream caused by gravity
Current shear – Variation of flow rate transverse to flow direction
Current (stream) – Flow of water in a stream caused by gravityPages displaying short descriptions of redirect targets
CURV – Early remotely operated underwater vehicle
Cylinder band – Straps to clamp two scuba cylinders together
Cylinder pressure gauge – Instrument for measuring gas pressure in a storage cylinder
Cylinder valve (disambiguation)
D
Dacor (scuba diving) – Former American diving equipment manufacturer
Dalton's law – Empirical law of partial pressures
The Darkness Beckons – History of UK cave diving by Martyn Farr
Damant, Guybon Chesney Castell – English physiologist, diver, royal navy officer, and researcher
DAN Asia-Pacific – Regional organisation of the Divers Alert Network
DAN Brasil – Regional organisation of the Divers Alert Network
DAN Europe – Regional organisation of the Divers Alert Network
DAN Japan – Regional organisation of the Divers Alert Network
DAN Southern Africa – Regional organisation of the Divers Alert Network
DAN World – Organisation of the Divers Alert Network covering other regions
Darwin's Arch – Rock arch near Darwin Island (collapsed 2021)
Davis Submerged Escape Apparatus – Early submarine escape oxygen rebreather also used for shallow water diving.
Davis, Robert – English inventor and manufacturer of underwater breathing apparatus
Day, John – First recorded death in a diving chamber
D-BRUV – Downward looking baited remote underwater video
DDRC Healthcare – British hyperbaric medical organisation
Dead space (physiology) – Inhaled air not part of gas exchange
Deadspace (in breathing apparatus) – Inhaled air not part of gas exchange
Deadweight anchor – Anchor that relies on weight and friction for holding
Deane, Charles Anthony – Pioneering diving engineer and inventor of a surface supplied diving helmet
Decima Flottiglia MAS – Italian naval commando frogman unit of the Fascist era
Deck decompression chamber – Hyperbaric chamber suitable for surface decompression or emergency use at a dive site
Decompression algorithm – Procedure to calculate the decompression needed for a given dive profile
Decompression bar – Horizontal bar suspended below the water surface at a decompression stop
Decompression buoy – Inflatable surface marker buoy deployed from underwater
Decompression chamber operation – Operation of a hyperbaric chamber in support of underwater diving
Decompression computer – Instrument to calculate decompression status in real time
Decompression cylinder – Scuba cylinder carrying decompression gas
Decompression (diving) – Pressure reduction and its effects during ascent from depth
Decompression equipment – Equipment used by divers to facilitate decompression
Decompression gas – Oxygen-rich gas used for accelerated decompression
Decompression illness – Disorders arising from ambient pressure reduction
Decompression model – Conceptual explanation forf decompression that helps formulate predictions
Decompression modelling – Using conceptual explanation forf decompression to help formulate predictions
Decompression monitoring equipment – Equipment for monitoring depth and run time of a dive, and decompression status
Decompression obligation – Physiological requirement for decompression to reduce risk of injury
Decompression practice – Techniques and procedures for safe decompression of divers
Decompression schedule – A specified ascent rate and series of increasingly shallower decompression stops
Decompression sickness – Disorder caused by dissolved gases forming bubbles in tissues
Decompression status – The theoretical level of inert gas content of the body tissues
Decompression stop – Pause needed during the ascent from a dive
Decompression stress – Combined influences on formation of decompression gas bubbles
Decompression theory – Theoretical modelling of decompression physiology
Decompression trapeze – Horizontal bars suspended at decompression stop depths
Deep air diving – Underwater diving beyond accepted limits for breathing air
Deep air diving blackout – Loss of consciousness due to extreme nitrogen narcosis
DeepC – Autonomous underwater vehicle powered by a fuel cell
Deep Diver – Research submersible
Deep diving – Underwater diving to a depth beyond the norm accepted by the associated community
Deep Drone – US Navy remotely operated underwater vehicle
DeepFlight Merlin – 3-seater wet sub diver propulsion vehicle
Deepsea Challenger – Bathyscaphe designed to reach the bottom of Challenger Deep
Deepspot – Deep swimming pool in Poland
Deep-submergence rescue vehicle – Submersible used for rescue of people from disabled submarines and submersibles
Deep stop – Decompression stops at depths significantly deeper than indicated by conventional algorithms
Deep water blackout (disambiguation)
Deep water submersible – Self-propelled deep-diving crewed submersible
Defence Diving School – Diver training centre in Hampshire, UK
Defense against swimmer incursions – Methods of protection from incursions by divers and swimmers
Delta-P (hazard) – Underwater hazard due to horizontal pressure differential
Demand controlled breathing apparatus – Equipment that supplied breathing gas only when required
Demand helmet – Diving helmet supplied with gas through a demand valve
Demand valve oxygen therapy – Use of high inhalation concentrations of oxygen as medical treatment
Demister (scuba) – Surfactant applied to prevent the condensation of water as droplets on a mask or helmet viewport
Demobilise (diving) – The dismantling, packing and transport back to storage of the dive spread
Demographics of recreational diving – Population distribution of recreational divers
Demographics of scientific divers – Population distribution of scientific divers
Denayrouze, Auguste – French inventor of a demand air supply regulator for underwater diving
Dental barotrauma – Damage to a tooth caused by a change of ambient pressure
Department of Employment and Labour – Department of the South African government responsible for matters related to employment
Depth blackout – Loss of consciousness due to deep diving while breathing air
Depth gauge – Instrument that indicates depth below a reference surface
DEPTHX – Autonomous underwater vehicle for exploring sinkholes in Mexico
Descending and ascending (diving) – Procedures for safe ascent and descent in underwater diving
DESCO – American manufacturer of commercial diving equipment
Developed pressure – Working pressure corrected for actual temperature
Diamond Reef System – System for training divers in buoyancy, trim and maneuvering skills
Diffuser (breathing set part) – Component fitted over the exhaust outlet to break up the exhaled gas
Diffusion – Transport of dissolved species from the highest to the lowest concentration region
Diluent flush – Rebreather diving safety procedure
Diluent gas – Metabolically inert gas in a breathing mixture
DIN 7876 – German standard for manufacture of swimfins
Directed search – Searches directed from the surface
Disappearance of Ben McDaniel – Scuba diver who disappeared during or after a cave dive
Distance line/dive reel/guide line – Line deployed by scuba divers for navigation
Diuresis – Increase in urine production
Dive boat – Boat used for the support of scuba diving operations
Dive boat operation – Operational procedures for a boat supporting diving
Dive boat skipper – Person in command of a dive boat
Dive briefing – Meeting of the dive team to discuss details before the diving operation
Dive center – Service organisation providing recreational diver training, equipment and dive outings
Dive computer , also known as Decompression computer – Instrument to calculate decompression status in real time
Dive cylinder – Cylinder to supply breathing gas for divers
Dive guide (disambiguation)
Dive guide (publication) – Travel guides for recreational diving
Dive leader – Recreational diving certification and role
Dive Leader – Recreational diving certification
Dive light – Light used underwater by a diver
Dive log – Record of diving history of an underwater diver
Divemaster – Recreational dive leader certification and role
Dive planning – The process of planning an underwater diving operation
Dive profile – Diver's pressure exposure over the time of a dive
Dive school – Establishment for diver training
Dive skins – Thin exposure suit to protect the skin in warm water
Dive spool – Simple flanged cylindrical line-holder
Dive suit – Garment or device designed to protect a diver from the underwater environment
Dive supervisor – Professional diving team leader responsible for safety
Dive Supervisor – Recreational dive leadership certification
Dive tables – Data used to determine a decompression schedule for a given dive profile and breathing gas
Dive team – A group of people working together to enhance dive safety and achieve a task
Dive timer – Electronic timer that automatically records the run time of a dive
Dive weights – Ballast weights carried by divers to counteract buoyancy of equipment
Dive-float – Small buoy towed by an underwater diver to indicate presence
Dive supervision – The work of the manager of a professional diving team
Dive/surface valve – Valve on a rebreather mouthpiece to isolate the breathing loop when not in use
Diver, The – Sculpture by John Kaufman
Diver (United States Navy) – US Navy personnel qualified in underwater diving and salvage
Diver certification – Certification as competent to dive to a specified standard
Diver certification agency – Organisation which issues certification for competence in diving skills
Diver certification equivalences – Comparison between certifications by different agencies
Diver certification organisation – Organisation that issues certificates of competence to underwater divers
Diver communications – Methods used by underwater divers to communicate
Diver detection sonar – Acoustic location systems to detect divers and submerged swimmer delivery vehicles
Diver down flag – Flag signal indicating divers are in the water nearby
Diver hand signals – Hand signals used for communication with divers
Diver lift – Movable platform for lifting a diver from the water to deck level
Diver medical technician – Paramedic with special training in diving medical emergencies
Diver navigation – Underwater navigation by scuba divers
Diver organisations – Memberhip organisations of underwater divers
Diver propulsion vehicle – Powered device for diver mobility and range extension (DPV)
Diver rescue – Rescue of a distressed or incapacitated diver
Diver safety – Risk management by and for the diver
Diver searches – Underwater searches carried out by divers.
Diver surface detection aids – Equipment to make a surfaced diver easier to find
Diver training – Processes to develop the skills and knowledge to dive safely underwater
Diver training manual – Documentary training aid used for training underwater divers
Diver training organization – Organization which provides training in diving skills or knowledge
Diver training organizations – Organization which provides training in diving skills or knowledge
Diver training standard – Document describing requirements of a diver training programme
Diver training tank – Tank of water to practice diving skills
Diver trim – Balance and orientation skills of an underwater diver
Diver voice communications – Protocol for spoken communications in diving operations
Diver weighting system – Ballast carried by underwater divers to counteract buoyancy
Diver weighting systems – Ballast carried by underwater divers to counteract buoyancy
Diver's air pump – Manually powered surface air supply for divers
Divers Academy International – Technical educational institution in New Jersey that offers training in commercial diving
Divers Alert Network (
DAN ) – International group of not-for-profit organizations for improving diving safety
Divers Alert Network America – A not-for-profit diving safety organization based in the US
Divers Alert Network Asia-Pacific – A not-for-profit diving safety organization based in Australia
Divers Alert Network Europe – A not-for-profit diving safety organization based in Europe
Divers Alert Network publications
Divers Alert Network Southern Africa – A public benefit diving safety organization based in South Africa
Diver's attendant – Assistant for a diver
Diver's cutting tool – A tool to assist in extricating the diver from entrapment by lines or nets
Diver's harness – Item fastened around a diver which allows the diver to be lifted
Divers Institute of Technology – Private, commercial educational institution for the training of commercial divers
Diver's knife – A tool to assist in extricating the diver from entrapment by lines or nets
Diver's logbook – Record of diving history of an underwater diver
Diversnight – Annual recreational night diving festival.
Diver's pump – Manually powered surface air supply for divers
Diver's safety harness – Harness suitable for lifting a diver out of the water
Diver's telephone – Hard wired diver communications equipment
Diver's tender – Assistant to a diver
Diver's umbilical – A hose and cable bundle which supplies breathing gas, communications and other services to a diver
Divex – Scottish provider of diving equipment and related services.
Diviac – Online booking site for diving holidays
Diving accident – Accident occurring while diving underwater
Diving activities – Things people do while diving underwater
Diving air compressor , also known as Diving compressor – Machine used to compress breathing air for use by underwater divers
Diving air compressor operator – Person who operates a diving air compressor
Diving air filter – Device to purify compressed breathing air
Diving air pump – Manually powered surface air supply for divers
Diving attendant – Member of a dive team responsible for assisting the diver
Diving at Work Regulations 1997 – UK legislation regulating all aspects of professional diving
Diving basket – Platform for lowering and lifting a diver through the water
Diving bell – Chamber for transporting divers vertically through the water
Diving boat – Boat used for the support of scuba diving operations
Diving buddy – Diver who dives as one of a buddy pair
Diving certification – Evidence of having been trained to a standard
Diving chamber – Hyperbaric pressure vessel for human occupation used in diving operations
Diving chamber operation – Operation of a hyperbaric chamber in support of underwater diving
Diving compass – Compass intended for diver navigation
Diving contractor – The legal persona responsible for professional diving operations for a client
Diving cylinder – Cylinder to supply breathing gas for divers
Diving destination – Places where recreational divers go on vacation
Diving Diseases Research Centre (
DDRC ) – British hyperbaric medical organisationPages displaying short descriptions of redirect targets
Diving disorders – Physiological disorders resulting from underwater diving
Diving environment – Characteristics of an environment in which underwater diving takes place
Diving equipment – Equipment used to facilitate underwater diving
Diving equipment maintenance and testing – Ensuring that the equipment is safe to use
Diving equipment technician – Person who maintains, repairs and tests diving and support equipment
Diving fatalities – Deaths associated with underwater diving
Diving flag – Flag signal indicating divers are in the water nearby
Diving gas analysis – Measuring the components in a breathing gas blend
Diving glove – Hand protection worn while driving
Diving half-mask – Mask covering the nose and eyes of an underwater diver
Diving hand signals – A form of sign system used to communicate underwater
Diving harness – Item fastened around a diver which allows the diver to be lifted
Diving hazards – Agents and situations that pose a threat to the underwater diver
Diving heavy – Underwater diving while intentionally negatively buoyant
Diving helmet – Rigid head enclosure with breathing gas supply worn for underwater diving
Diving incident and accident investigation – Forensic investigation of underwater diving accidents
Diving instructor – Person who trains and assesses underwater divers
Diving Instructor – Person who trains and assesses underwater divers
Diving jackstay – Form of guideline laid between two points to guide the diver
Diving jargon – Definitions of jargon, diver slang and acronyms used in underwater diving
Diving ladder – Ladder to facilitate egress from the water by divers
Diving law – Laws directly affecting diving activities
Diving legislation – Legislation directly affecting diving activity
Diving light – Portable light source for use underwater
Diving line signals – Standard signals coded in the form of tugs on the diver's lifeline
Diving locations – Places that divers go to enjoy the underwater environment
Diving logbook – Record of diving history of an underwater diver
Diving mask – Watertight air-filled face cover with view-ports for improving underwater vision
Diving Medical Advisory Council (
DMAC ) – Independent organisation of diving medical specialists from Northern Europe
Diving medical examination – Assessment of medical fitness to dive
Diving medical examiner – A medical practitioner registered to assess medical fitness to dive
Diving Medical Examiner – A medical practitioner registered to assess medical fitness to dive
Diving medical practitioner – Specialist in diagnosis, treatment and prevention of disorders caused by underwater diving
Diving Medical Practitioner – Specialist in diving medicine
Diving medical technician – Person trained in advanced first aid for divers
Diving Medical Technician – Person trained in advanced first aid for divers
Diving medicine – Diagnosis, treatment and prevention of disorders caused by underwater diving
Diving mode – The conceptual methods of underwater diving
Diving operation – Underwater dive and support activities to achieve a specific goal
Diving operations record – Documentation recording a professional dive
Diving physics – Aspects of physics which affect the underwater diver
Diving physiology – Influences of the underwater environment on the physiology of human divers
Diving platform (scuba) – Low freeboard platform on a dive boat to give divers easy access to the water
Diving procedures – Standardised methods of doing things that are known to work effectively and acceptably safely
Diving rebreather – Closed or semi-closed circuit scuba
Diving reflex – The physiological responses to immersion of air-breathing vertebrates
Diving regulations – Stipulations of the delegated legislation regarding the practice of underwater diving
Diving regulator – Mechanism that controls the pressure of a breathing gas supply for diving
Diving regulator malfunction – Failure modes of breathing gas control valves for underwater diving
Diving response – The physiological responses to immersion of air-breathing vertebrates
Diving safety – Risk management of underwater diving activities
Diving safety equipment – Equipment used to facilitate underwater diving safety
Diving safety harness – A harness by which the diver can safely be lifted
Diving safety officer – Administrator of a US university's research diving safety program
Diving school – Establishment for training and assessing underwater divers
Diving Science and Technology (
DSAT ) – PADI affiliate and developer of recreational decompression planning tools
Diving shot , also known as Shot line – Substantial weighted near-vertical line with buoy
Diving signal – Signals made by divers for communication
Diving skins – Suit worn to protect the skin from jellyfish stings, abrasion and sunburn
Diving spread – The topside base for commercial diving operations
Diving stage – A platform on which one or two divers stand which transports them vertically through the water
Diving suit – Garment or device designed to protect a diver from the underwater environment
Diving suit hood – Protective headgear worn by underwater diver
Diving superintendent – A management position responsible for diving operations
Diving supervisor – Professional diving team leader responsible for safety
Diving support equipment – Equipment used in the support of an underwater diving operation
Diving support vessel – Ship used as a floating base for professional diving projects
Diving systems technician – A competent person who maintains and repairs diving life-support equipment
Diving team – Group of people working together to enhance dive safety and achieve a task
Diving team tools and equipment – Equipmemt shared by the members of a diving team
Diving terminology – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Diving terms – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Diving theory – The knowledge required for safe diving
Diving tourism – Tourism focused on recreational diving activities
Diving tourism industry – Industry based on recreational diver travel
Diving Unlimited International – American manufacturer of dry suits and other diving equipment
Diving watch – Watch designed for underwater diving
Diving weight – Ballast carried by a diver to counteract buoyancy or adjust trim
Diving weighting system – Ballast carried to counteract buoyancy
Doing It Right (scuba diving) (
DIR ) – Technical diving safety philosophy
Donald, Kenneth William – British expert on underwater and exercise physiology.
Downline (diving) – Rope from the surface to an underwater workplace
Downstream scuba manifold – Component used to functionally connect scuba cylinders
Downstream valve – Valve which is opened along the pressure differential
Dräger (company) – German manufacturer of breathing equipment
Dräger DM20 oxygen rebreather system – Oxygen rebreather system for copper helmet
Dräger DM40 mixed gas rebreather system – Nitrox rebreather system for copper helmet
Dräger Dolphin – Semi-closed circuit recreational diving rebreather
Dräger Modell 1915 Bubikopf helmet – Copper helmet for rebreather systems
Dräger Ray – Semi-closed circuit diving rebreather
Drift diving – Scuba diving where the diver is intentionally transported by the water flow
Drill Master diving accident – Fatal diving bell accident off Norway in 1974
Drop tank (scuba) – Scuba set placed along the guideline on a cave dive for later use
Drowning – Respiratory impairment resulting from being in or underneath a liquid
Dry bell – Hyperbaric chamber for transporting diversvertically through the water
Dry Combat Submersible – Midget submarine project
Dry suit – Watertight clothing that seals the wearer from cold and hazardous liquids
Dry suit blowup – Over-inflation of a dry suit causing uncontrolled ascent
Dry suit diver – Certification for diving in a dry suit
Dry suit inflation cylinder – Diving cylinder dedicated for suit inflation gas
Dry suit inflation hose – Low pressure inflation gas supply
Dry suit inflation valve – Manual valve to admit low pressure gas into a diving dry suit
DSRV-2 Avalon – Mystic-class deep-submergence rescue vehicle
DSV-5 Nemo – Submersible used by the United States Navy
DSV Alvin – Crewed deep-ocean research submersible
DSV Bakunawa – Crewed full ocean depth rated submersible
DSV Fendouzhe – Chinese deep submergence vehicle
DSV Limiting Factor – Crewed full ocean depth rated submersible
DSV Sea Cliff – US Navy crewed deep-ocean research submersible
DSV Shinkai – Crewed research submersible
DSV Shinkai 2000 – Japanese crewed research submersible
DSV Shinkai 6500 – Japanese crewed research submersible
DSV Turtle – US Navy crewed deep-ocean research submersible
Dual bladder buoyancy compensator – Scuba diving buoyancy compensator with redundant air bag
Duckbill valve – Type of check valve
Dump valve (diving) – Pressure relief and manual vent on diving buoyancy compensator
Dutch Underwater Sports Association – Dutch governing body for underwater sports
Duty of care – Type of legal obligation
Dwell time (filtration) – Time that fluid spends passing through active filter medium
Dynamic apnea – Freediving disciplines where the diver swims horizontally under water
Dynamic compression of the airways , also known as Dynamic airway compression – Mechanism reducing lung airway section area during forced expiration
Dynamic positioning – Automatic ship station- and heading-holding systems
Dynamically positioned vessel (
DPV ) – Ship with automatic station- and heading-holding systems
Dysbaric osteonecrosis – Ischemic bone disease caused by decompression bubbles
Dysbarism – Medical conditions resulting from changes in ambient pressure
E
F
Feather breathing – Technique for minimising gas loss during some regulator malfunctions
Federación Española de Actividades Subacuáticas (
FEDAS ) – Spanish national federation for underwater activities, affiliated to CMAS
Fédération Française d'Études et de Sports Sous-Marins (
FFESSM ) – French diver training and certification agency
Federazione Italiana Attività Subacquee (
FIAS ) – Italian non-profit recreational diver training organisation affiliated to CMAS
Feet fresh water – Unit of pressure equal to 1/34 atm.
Fenzy – French manufacturer of industrial and diving breathing equipment
Fernez, Maurice – French inventor and pioneer in underwater breathing apparatus
Ferraro, Luigi – Officer of the Royal Italian Navy and pioneer of Italian submarine warfare
Fibre wound composite cylinder – Pressure vessel with fiibre structural reinforcement
Fick's laws of diffusion – Mathematical descriptions of molecular diffusion
Fife, William Paul – US Air Force officer and hyperbaric medicine researcher
Filling whip – High pressure hose for filling compressed gas cylinders
Fin retainer – Rubber straps for securing swimfins to the feet
Finning techniques – Techniques used by divers and surface swimmers using swimfins
Finswimming – Competitive watersport using swimfins for propulsion
Finswimming at the 2001 World Games – Competition held in Akita, Japan
Finswimming at the 2001 World Games – Men's 50 m apnoea – Competition held in Akita, Japan
Finswimming at the 2005 World Games – Men's 50 m apnoea – Competition held in Duisburg, Germany
Finswimming at the 2009 Asian Indoor Games – Competition held in Mỹ Đình National Aquatics Sports Complex, Hanoi, Vietnam
Finswimming at the 2009 World Games – International competition in Kaohsiung
Finswimming at the 2009 World Games – Men's 50 m apnoea – Event in Kaohsiung, Taiwan
Finswimming at the 2011 SEA Games – Watersport competition in Palembang, Indonesia
Finswimming at the 2021 SEA Games – Competition at Mỹ Đình Aquatics Center in Hanoi, Vietnam
Finswimming at the 2023 SEA Games – Competions held at Phnom Penh, Cambodia
Finswimming at the World Games – Trend sport at the World Games
Finswimming in Australia – Competitive watersport
Finswimming in the United Kingdom – Competitive watersport
Finswimming in the United States – Competitive watersport
Finswimming World Championships – International event for the underwater sport of finswimming
First aid – Emergency first response medical treatment
Fischer, George R. – American underwater archaeologist
Fitness to dive , also known as fitness for diving – Medical fitness of a person to function safely underwater under pressure
Fleuss, Henry – British inventor of diving equipment
Flicker fusion threshold – Concept in the psychophysics of vision
Flushing the loop – Rebreather diving safety procedure
Flying after diving – Precautions against decompression sickness when ascending to altitude after diving
FNRS-2 – First bathyscaphe
FNRS-3 – Bathyscaphe of the French Navy
Force – Influence that can change motion of an object
Formoza Military Unit – Polish Special Forces unit
Fraction of inspired oxygen – Volumetric proportion of oxygen to other constituents in a breathing gas
Franzén, Anders – Swedish marine technician and amateur naval archaeologist
Free immersion apnea – Human-powered freediving discipline
Free-flow diving helmet , also known as Free-flow helmet – Helmet which supplies a continuous flow of air to the diver
Freediving – Underwater diving without breathing apparatus
Freediving blackout – Loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive
Freeflow – A state of continuous flow of breathing gas in an underwater breathing apparatus
Free-flow breathing apparatus – Equipment which provides a constant flow of breathing gas
French commando frogmen – Combat swimmer unit of the French Navy
Frenzel maneuver – Ear equalization technique originally developed for dive bomber pilots
Fresh gas flow (disambiguation) – Gas added to the recycled gas of a rebreather or anesthetic machine
Freshwater diving – Underwater diving in fresh water
Frog kick – Finning propulsion kick used particularly by cave and wreck divers
Frogman – Tactical scuba diver
Frogman Corps (Denmark) – Danish maritime special operations unit
FROGS (Full Range Oxygen Gas System) – Closed circuit oxygen diving rebreather
Fuerzas Especiales – Special forces unit of the Mexican Navy
Fukuryu – Japanese divers intended to manually detonate mines on invading ships
Full-face diving mask – Diving mask that covers the mouth as well as the eyes and nose
Full facepiece – User respiratory inteface with breathing apparatus that covers the nose, mouth and eyes
Full-face snorkel mask – Breathing apparatus for surface swimming
Full ocean depth – Maximum known depth in the ocean
G
Gaiters (diving) – Accessories used to restrict volume of a dry suit over the lower legs
Gas blender – Person who blends breathing gas mixtures for scuba diving and fills diving cylinders
Gas blending – Producing special gas mixtures to specification
Gas blending for scuba diving – Mixing and filling cylinders with breathing gases for use when scuba diving
Gas booster – Machine to increase the pressure of compressed gas
Gas endurance – The time a gas supply will last
Gas exchange – Process by which gases diffuse through a biological membrane
Gas extender – Type of semi-closed circuit diving rebreather
Gas-integrated dive computer – A dive computer that displays the pressure of breathing gas remaining in the cylinder
Gas laws – Scientific description of the behaviour of gases as physical conditions vary
Gas man – Person who controls the breathing gas supply to a surface-supplied mixed-gas diver
Gas man (diving) – Member of a surface-supplied diving team who operates the breathing gas panel
Gas matching – Ensuring that reserve breathing gas is sufficient to supply the dive buddy
Gas panel – Breathing gas distribution panel for surface-supplied diving
Gas panel operator – Member of a surface-supplied diving team who operates the breathing gas panel
Gas-reclaim system – Equipment to recover exhaled gas from a diver to tecover the helium content
Gas storage bank – Group of similar size high pressure cylinders mounted together and connected to a common manifold
Gas storage quad – Group of similar size high pressure cylinders
Gas storage tube – Large volume, high pressure gas storage cylinder
Gas switch – Changing the breathing gas mixture during a dive
Gas switching – Changing the breathing gas mixture during a dive
Gas toxicity – Degree of harmfulness of gases
Gay-Lussac's law – Relationship between pressure and temperature of a gas at constant volume
German commando frogmen – German postwar commando amphibious warfare force
Global Explorer ROV – Deep water science and survey remotely operated vehicle
Global Underwater Explorers (
GUE ) – Recreational/technical scuba training and certification agency
Glossary of breathing apparatus terminology – Definitions of technical terms used in connection with breathing apparatus
Glossary of underwater diving terminology , also known as Glossary of underwater diving terms or Glossary of SCUBA diving – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Glossary of underwater diving terminology: A–C – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Glossary of underwater diving terminology: D–G – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Glossary of underwater diving terminology: H–O – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Glossary of underwater diving terminology: P–S – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Glossary of underwater diving terminology: T–Z – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Goldfinder – Autobiography of British diver and treasure hunter Keith Jessop
Gold Rush: White Water – American television series
Goldfish-class ROUV – Light class of Chinese remotely operated underwater vehicle
Goodman handle – Mounting which holds a dive light on the back of the diver's hand
Gradient factor – Method for adjusting conservatism of decompression algorithms
Gradient factor in decompression modelling – A way for users to adjust the conservatism of a decompression algorithm in software
Green Fins – Organisation in South East Asia for preservation of coral reefs by improving diver behavior
GROM Military Unit – Polish special forces unit
GRUMEC , also known as Brazilian commando frogmen – Brazilian Navy special forces diving unit
Guide line – Line deployed by scuba divers for navigation
Gyrojet – Firearm that fires small rocket projectiles
H
Haenyeo – Female divers of Jeju, South Korea
Halcyon PVR-BASC – Semi-closed circuit depth compensated passive addition diving rebreather
Halcyon RB80 – Non-depth-compensated passive addition semi-closed circuit rebreather
Haldane, John Scott – British physiologist and decompression researcher (1860–1936)
Haldane's decompression model – Decompression model developed by John Scott Haldane
Half + 15 bar – Rule of thumb for scuba gas management
Half mask – Diving mask covering the nose and eyes
Half time (physics) – The time taken for a quantity to decrease by half in an exponential decay process
Halocline – Stratification of a body of water due to salinity differences
Hamilton, Robert William Jr. – American physiologist and researcher in hyperbaric physiology.
Hand-off a cylinder – Transfer a scuba cylinder from one diver to another in the water
Hand-off cylinder – Scuba set that can be passed to another diver
Hans Hass Award – Award in recognition of contribution made to the advancement of our knowledge of the ocean
Hans Hass – Austrian biologist, film-maker, and underwater diving pioneer
Hawaiian sling – Simple form of underwater speargun
Hazard – Situation or object that can cause damage
Hazard analysis (
HAZID ) – The identification of present hazards as the first step in a process to assess risk
Hazard elimination – Hazard control by removing the hazard
Hazard substitution – Replacing a material or process with a lower risk alternative
Hazardous Materials Identification System – Numerical hazard rating using colour coded labels
Hazards of the aquatic environment – Hazards inherent to being underwater
Hazards of the specific diving environment – Factors which vary between diving environments
Hazmat diver – Professional diver working in hazardous materials environments
Hazmat diving – Underwater diving in a known hazardous materials environment
Hazmat diving decontamination – Removing hazardous environmental contaminants from the diver after a dive
H-BRUV – Horizontally aligned baited remote underwater video
Health and Safety Executive (
HSE ) – United Kingdom government agency
Healthways (scuba gear company) – Defunct firm which made scuba gear
Heckler & Koch P11 – Five-barreled underwater rocket dart pistol
Heinke (diving equipment manufacturer) – British manufacturer of diving equipment
HeinrichsWeikamp – German manufacturer of dive computers and other underwater electronics for recreational diving.
Helgoland Habitat – Ambient pressure underwater habitat
Heliair – Breathing gas mixed from air and helium
Helicopter Aircrew Breathing Device , also known as helicopter escape set – Small scuba device for escape from ditched helicopters
Helicopter turn – Rotation about a vertical axis by an underwater diver using only fins
Heliox – A breathing gas mixed from helium and oxygen
Helium analyzer , also known as Helium analyser – Instrument to measure the concentration of helium in a gas mixture
Helium reclaim system – System for recovering exhaled breathing gas
Helium release valve – Feature on some watches for saturation diving
Helium speech unscrambler – Technology for reducing hyperbaric speech distortion
Helix Energy Solutions Group – Provider of offshore services and ROV operations
Helmet squeeze – Type of injury caused by a pressure difference between the inside and outside of a diving helmet
Helmet weight – Ballast added to a diving helmet to prevent it from floating
Hempleman, Henry Valence – British decompression researcher
Henry's law – Gas law regarding proportionality of dissolved gas
Hierarchy of hazard controls – System used in industry to eliminate or minimize exposure to hazards
High pressure breathing air compressor – Machine to provide atmospheric air at high pressure for breathing
High pressure storage cylinder – Container for storing gases at high pressure
High-pressure nervous syndrome – Reversible disorder caused by breathing helium based gas below about 150 m
High-pressure water jetting – The use of very high pressure water for removing contamination and coatings from hard surfaces
Hill, Leonard Erskine – British physiologist and diving physiology researcher
Hills, Brian Andrew – Physiologist who worked on decompression theory
History of decompression research and development – Chronological list of notable events in the history of diving decompression.
History of Diving Museum – Museum of underwater diving in Islamorada, Florida
History of scuba diving – History of diving using self-contained underwater breathing apparatus
History of underwater diving – Developments over time in the human activity
Hoppe-Seyler, Felix – German physiologist and chemist (1825–1895)
Hogarthian scuba configuration – Scuba harness arrangement developed by Bill Main
Hoke valve – Gas recirculation control valve on MK V helium hemet
Hookah (diving) – Surface-supplied diving equipment without the communication, lifeline and pneumofathometer hose
Hookah diving – Underwater diving using a basic air hose from the surface
Hot water suit – A wetsuit with a supply of heated water to keep a diver warm
Hot water system (diving) – Water heating and supply system for hot-water diving suits
Huggins, Karl E. – American decompression researcher
Human factors in diving equipment design – Influence of the interaction between the user and the equipment on design
Human factors in diving safety – The influence of physical, cognitive and behavioral characteristics of divers on safety
Human factors in the design of diving equipment – Influence of the interaction between the user and the equipment on design
Human physiology of underwater diving , also known as Human physiology of diving – Influences of the underwater environment on the physiology of human divers
Human torpedo – Early form of diver propulsion vehicle
Hydraulic chainsaw – Chainsaw powered by a hydraulic motor
Hydreliox – Breathing gas mixture of hydrogen, helium, and oxygen
Hydrocleaning – Use of a water jet for cleaning hard surfaces
Hydrogen narcosis – Psychotropic state induced by breathing hydrogen at high partial pressures
Hydrogen sulfide – Poisonous, corrosive and flammable gas
Hydrophobe – Molecule or surface that has no attraction to water
Hydrostatic pressure – The static pressure exerted by the weight of the fluid column above the point
Hydrostatic test – Non-destructive test of pressure vessels
Hydrox (breathing gas) – Breathing gas mixture experimentally used for very deep diving
Hyperbaric evacuation and rescue – Emergency transport of divers under a decompression obligation to a place of safety
Hyperbaric evacuation facilities – Systems to evacuate saturation divers in an emergency
Hyperbaric evacuation system – Equipment for emergency transport of divers under a decompression obligation to a place of safety
Hyperbaric evacuation unit – Pressure vessel in which divers are transported under pressure in an emergency
Hyperbaric lifeboat – Lifeboat for transporting people under pressure
Hyperbaric medicine – Medical treatment at raised ambient pressure
Hyperbaric nursing – Nursing specialty involved with hyperbaric oxygen therapy
Hyperbaric oxygen treatment – Medical oxygen treatment at raised pressure
Hyperbaric oxygen treatment table – Planned hyperbaric exposure using oxygen breathing gas as medical treatment
Hyperbaric reception facility – Saturation facility on standby in case evacuation is necessary
Hyperbaric rescue vessel – Ship to recover hyperbaric evacuation units
Hyperbaric speech distortion – Speech distortion at high ambient pressure
Hyperbaric stretcher – Portable pressure vessel to transport a person under pressure.
Hyperbaric treatment – Medical treatment at raised ambient pressure
Hyperbaric treatment schedules – Planned hyperbaric exposure using a specified breathing gas as medical treatment
Hyperbaric treatment tables – Planned hyperbaric exposure using a specified breathing gas as medical treatment
Hyperbaric welding – Welding metal at elevated pressure
Hypercapnia – Abnormally high tissue carbon dioxide levels
Hyperoxia – Exposure of tissues to abnormally high concentrations of oxygen.
Hyperthermia – Elevated body temperature due to failed thermoregulation
Hyperventilation – Excessive breathing
Hyperventilation-induced blackout – Loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive
Hypobaric decompression – Reduction in pressure to lower than normal sea level atmospheric pressure
Hypocapnia – State of reduced carbon dioxide in the blood
Hypothermia – Human body core temperature below 35.0 °C (95.0 °F)
Hypoventilation – Insufficient breathing
Hypoxia (medicine) – Medical condition of lack of oxygen in the tissues
Hypoxia of ascent – Loss of cosciousness during ascent from a breathhold dive
Hypoxic blackout – Loss of consciousness due to cerebral hypoxia
Hypoxic trimix diver – Recreational technical diving certification level
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Lambertsen Amphibious Respiratory Unit (
LARU ) – Early closed circuit oxygen diving rebreather
Lambertsen, Christian J. – American environmental and diving medicine specialist
LAR-5 – Military oxygen tebreather by Drägerwerk
LAR-6 represented by
Drägerwerk – German manufacturer of breathing equipment
LAR-V represented by
Drägerwerk – German manufacturer of breathing equipment
Laryngospasm – Involuntary contraction of the vocal folds restricting inhalation
The Last Dive – Non-fiction book by Bernie Chowdhury about a double wreck diving fatality
Latent hypoxia – Lung gas and blood oxygen concentration sufficient to support consciousness only at depth
Launch and recovery system (diving) – Equipment used to deploy and recover a diving bell, stage, or ROV
Lazy shot – A diving shotline which does not reach the bottom
Legal aspects of underwater diving , also known as Legal aspects of diving – How diving activities are affected by law
Le Prieur, Yves – French naval officer and inventor of a free-flow scuba system
Life-support equipment – Equipment which is necessary to support life in a hostile environment
Life support supervisor – Senior life support technician
Life support technician – A member of a saturation diving team who operates the surface habitat
Life-support system – Technology that allows survival in hostile environments
Life support system operation – Operation of the systems which are necessary for the survival of the occupants
Lifeline (diving) – A rope connecting the diver to an attendant, usually at the surface
Lifting bag – Airtight bag used for underwater buoyant lifting when filled with air
Lightweight demand diving helmet , also known as Lightweight demand helmet – Underwater breathing apparatus
Lightweight diving helmet – Diving helmet supported by the head and neck
Limpet mine – A type of naval mine which is attached to a target by magnets
Line arrow – Marker used on cave guide lines to provide safety information to divers
Line holder – Simple device for storing and deploying line underwater
Line marker – Marker used on cave guide lines to provide safety information to divers
Lipid – Substance of biological origin that is soluble in nonpolar solvents
Liquid breathing – Respiration of oxygen-rich liquid by a normally air-breathing organism
List of British records in finswimming
List of Commonwealth records in finswimming
List of DAN publications – List of Divers Alert Network publications
List of designations under the Protection of Wrecks Act – All sites designated under the UK Protection of Wrecks Act
List of diver certification organisations – Agencies which issue certification for competence in diving skills
List of diver certification organizations – Agencies which issue certification for competence in diving skills
List of Divers Alert Network publications
List of diving environments by hazard – Example types of a class of diving hazard
List of diving environments by type – Variety of environments that people may dive in
List of diving hazards and precautions – Hazards associated with underwater diving
List of European records in finswimming
List of legislation regulating underwater diving – List of national and state legislation regulating underwater diving
List of military diving units
List of notable scuba divers – Hierarchical outline list of biographical articles about underwater divers
List of researchers in diving physiology and medicine
List of researchers in underwater diving
List of scuba divers – Hierarchical outline list of biographical articles about underwater divers
List of shipwrecks in international waters
List of shipwrecks of Africa
List of shipwrecks of Asia
List of shipwrecks of Europe
List of shipwrecks of Hong Kong
List of shipwrecks of North America
List of shipwrecks of Oceania
List of shipwrecks of South America
List of shipwrecks of the Isles of Scilly
List of shipwrecks of the Isles of Scilly (19th century)
List of signs and symptoms of diving disorders – Evidence of physiological disorders resulting from underwater diving
List of types of diving environments – Variety of environments that people may dive in
List of undersea explorers
List of underwater divers – List of underwater divers whose exploits have made them notable.
List of underwater diving hazards and precautions – Hazards associated with underwater diving
List of underwater explorers
List of United States Navy SEALs – Notable members of the US Navy SEALs and UDTs
List of United States records in finswimming
List of world records in finswimming
List of wreck diving sites – List of shipwreck sites which are popular amongst scuba divers for wreck diving.
Lists of shipwrecks – Index to Wikipedia's lists of shipwrecks
Little Blue Lake – Flooded sinkhole dive site in South Australia
Live-aboard dive boat – Boat providing accomodations and diving platform for multi-day trips
Live-boat diving – Diving from a boat which is under way (not moored)
Live-boating – Diving from a vessel under way
Liveaboard – Way of using a boat
Lobster hook – Implement for extracting lobsters from holes
Lockout–tagout (
LOTO ) – Safe isolation of dangerous equipment during maintenance or testing
London Diving Chamber Dive Lectures – Series of public lectures that have been hosted at the Royal Geographical Society in London
Long distance part of the 2011 Finswimming World Championships – International competition in Hódmezővásárhely, Hungary
Long term health effects of diving – Effects of frequent underwater diving on health
Long-Term Mine Reconnaissance System – American torpedo tube-launched underwater search and survey unmanned undersea vehicle
Longshore current – A current parallel to the shoreline caused by waves approaching at an angle to the shoreline
Longshore drift – Sediment moved by the longshore current
Loop rebreather – Rebreather architecture with one-way flow
Louis de Corlieu – French naval officer and inventor of the swimfin
Low Impact Diver – PADI specialty to improve poor buoyancy, trim and finning skills in recreational divers
Low impact diving – Scuba diving that has minimal environmental effect
Low pressure breathing air compressor – Machine to provide atmospheric air at low pressure for breathing
LR5 – Crewed submersible for submarine rescue
LR7 – Manned submersible undersea rescue vehicle
Lung over-pressure injury – Damage to lungs caused by internal overpressure
Lung overexpansion injury – Injury to the lungs caused by excessive internal pressure
Lung overpressure injury – Injury to the lungs caused by excessive internal pressure
Lunocet – Biomimetic monofin
Lyons Maritime Museum – Diving history museum in St. Augustine, Florida
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Magnesium torch – Bright light source made from magnesium, which burns underwater
Man in the Sea Museum – Diving history museum in Panama City Beach, Florida
Management of multiple cylinders – Techniques for carrying and using multiple scuba sets
Manifold (scuba) – Component to functionally connect scuba cylinders
Manifolded twin scuba set , also known as Manifolded twin set or manifolded twins – Two scuba cylinders functionally connected by a manifold
Manually controlled closed circuit rebreather – Rebreather in which the oxygen content of the loop gas is controlled by the diver
MARCOS – Indian Navy special operations force
Mares (scuba equipment) – Italian manufacturer of underwater diving equipment.
Marine Commandos – Marine special operations group of the Lebanese Army
Marinejegerkommandoen – Norwegian naval special operations unit
Maritime archaeology – Archaeological study of human interaction with the sea
Maritime Archaeology Sea Trust – Charitable trust in the UK
Maritime Archaeology Trust – Charitable organization in Great Britain
Mark IV Amphibian – British military oxygen rebreather
Mary Rose – Carrack-type warship of the English Tudor navy
Mass fraction blending – Mixing gas by measuring added mass of each component
Master diver (United States Navy) – Senior diver rating in US Navy
Master Instructor – Grade of recreational dive instructor with some experience
Master Scuba Diver – The highest non-leadership recreational scuba diver certification issued by some agencies
Maximum operating depth – Depth below which the partial pressure of oxygen (pO2) of the gas mix exceeds an acceptable limit
Maximum voluntary ventilation – Limit of amount than can be breathed in a minute
Maya AUV India – Autonomous underwater vehicle from National Institute of Oceanography, India
McCann Rescue Chamber – Device for rescuing submariners
Mechanical dead space – Space in breathing apparatus in which the breathing gas must flow in both directions
Mechanism of diving regulators , also known as Mechanism of the diving regulator – Arrangement and function of the components of regulators for underwater diving
Media diver – Professional diver working in the media sector
Media diving – Underwater diving in support of the media industries
Medical fitness to dive – The medical fitness of a person to function safely underwater under pressure
Medical oxygen – Oxygen used for therapeutic purposes
Medically fit to dive – State of a person who has no medical constraints preventing them from underwater diving
Membrane gas separation – Technology for splitting specific gases out of mixtures
Messenger line – Light line used to pull heavier cable or lower a package along a downline
Metabolism – Set of chemical reactions in organisms
Metre sea water , also known as metre seawater – Unit of pressure equal to one tenth of a bar
Middle ear barotrauma – Pressure injury to the middle ear
Midwater , also known as Mid-water – In the water column between surface and bottom
Military diver training – Training of underwater divers for service in the armed forces
Military diving – Underwater diving in a military context by members of an armed force
Mine escape set – Portable breathing apparatus intended for escape from compromised mines
Minedykkerkommandoen – Norwegian Navy clearance diver unit
Minentaucher – Mine clearance divers of the German Navy
Mini Rover ROV – Small, low cost observation class remotely operated underwater vehicle
Mir (submersible) – Self-propelled deep submergence vehicle
Missed decompression – Unsafe adcent from dive
Mission 31 – An undersea expedition organized by Fabien Cousteau
Mitchell, Simon – New Zealand physician and author on diving medicine
Mitigation – Reduction of something harmful or the reduction of its harmful effects
Mixed gas rebreather – Rebreather using gas other than only oxygen
Mk 1 Underwater Defense Gun – Underwater firearm developed by the United States during the Cold War
Mk V Mod 1 Heliox helmet – US Navy standard diving helmet modified for heliox
Mode of diving – The conceptual methods of underwater diving
Modulated ultrasound – Technology for transmitting signals through water
Moir, Ernest William – British civil engineer credited with inventing the first medical airlock
Molecular diffusion – Thermal motion of liquid or gas particles at temperatures above absolute zero
Momsen, Charles – US Navy admiral, submarine rescue (1896–1967)
Monkey diving – Sidemount diving with a single cylinder
Monofin – Single blade swimfin attached to both feet
Moon pool – Opening in the base of a hull, platform, or chamber giving access to the water below
Morse Diving – American manufacturer of diving equipment
Morse Engineering Mk 12 helmet – US Navy deep water free-flow helmet
Motion sickness – Nausea caused by motion or perceived motion
Motorised Submersible Canoe – WWII British frogman delivery vehicle
Mouth-to-mouth resuscitation – Artificial ventilation using exhaled air from the rescuer
Mouthpiece (breathing apparatus) – Respiratory user interface
Mouthpiece retaining strap – Safety item for scuba diving, particularly with a rebreather
MSDS Marine – British marine and coastal archaeological contractor
MSM-1 – Italian deep-submergence rescue vehicle
Msw – Metre of sea water, a unit of pressure
Muck diving – Recreational diving on a loose sedimentary bottom
Multi-level dive – Scuba diving in consecutively shallower depth ranges on one dive
Muscle-memory – Consolidating a motor task into memory through repetition
Mushroom valve – Arrangement and function of the components of regulators for underwater diving
M-value (decompression) – Maximum inert gas supersaturation allowed for a tissue in decompression theory}
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P2 – Svenskt Vrakskydd – Organization for presrvation of shipwrecks in Swedish waters
PADI Advanced Rebreather Diver – Minimum PADI certification meeting Rebreather Training Council standards
PADI AWARE – Marine conservation non-profit organization for recreational divers
PADI Delayed Surface Marker Buoy Diver – Diver trained to deploy a decompression buoy from depth
PADI Discover Scuba Diving – Introductory scuba experience without certification
PADI Low Impact Diver – Training to mitigate low entry level competence standards
PADI Open Water Diver – Entry level recreational diving certification
PADI Peak Performance Buoyancy – PADI diver with buoyancy control skill
Panic – Sudden overwhelming sensation of fear
Parachute lift bag – Open bottomed airtight bag used for underwater buoyant lifting when filled with air
Partial pressure – Pressure of a component gas in a mixture
Partial pressure blending – Gas blending based on pressure ratio of components
Partial pressure vacancy – Physiological effect of metabolism on the total dissolved gas concentration in venous blood
PASKAL – Special operations force of the Royal Malaysian Navy
Passive addition semi-closed circuit rebreather , also known as passive addition rebreather – Dumps gas from the breathing circuit and makes up volume on demand
Patent foramen ovale – A heart defect present at birth
Pearl hunting – Collecting pearls from wild molluscs
Pearling in Western Australia – Local aquaculture industry
Pendulum rebreather – Configuration using biderctional gas flow
Pendulum search – Diver search pattern
Penetration dive – Dive under a physical barrier to a direct vertical ascent to the surface
Penetration diving – Diving under a physical barrier to a direct vertical ascent to the surface
Peress, Joseph Salim – Pioneering British diving engineer
Performance Freediving International (
PI ) – Freediver training agency
Perfusion – Passage of fluid through the circulatory or lymphatic system to an organ or tissue
Permanent set – Plastic deformation
Permeation – Penetration of a liquid, gas, or vapor through a solid
Permit-to-work – Work safety management system
Personal diving equipment – Underwater diving equipment worn by the diver
Personal protective equipment – Equipment designed to help protect an individual from hazards
Philippine Underwater Hockey Confederation – National sports association
Phoenix International Holdings – Marine services company for underwater operations
Physiological effects of the use of breathing apparatus – Equipment allowing or assisting the user to breath in a hostile environmentPages displaying short descriptions of redirect targets
Physiological response to water immersion – Also known as the diving response and mammalian diving reflex
Physiology of decompression – The physiological basis for decompression theory and practice
Physiology of diving adaptations – Adaptations of marine vertebrates to diving
Physiology of human diving – Influences of the underwater environment on the physiology of human divers
Pillar valve represented by
Scuba cylinder valve – Valve controlling flow of breathing gas into and out of a scuba cylinder
Piccard, Auguste – Swiss physicist, inventor, and explorer
Pinch point hazard – Mechanical hazard which may damage or injure by reducing a gap
Pipeline end manifold – Termination of a rigid pipeline
Pneumofathometer – Instrument for measuring the depth of a diver by air pressure
Police diving – A branch of professional diving carried out by police services
Polespear – Basic rubber launched underwater fishing spear
Police diving – A branch of professional diving carried out by police services
Neal W. Pollock – Canadian researcher in diving physiology and hyperbaric medicine
Pony bottle – Small independent scuba cylinder usually carried for emergency gas supply
Pool part of the 2011 Finswimming World Championships – International competition in Hódmezővásárhely, Hungary
Pool part of the 2013 Finswimming World Championships – International competition in Kazan, Russia
Porpoise (rebreather) – Australian oxygen rebreather
Porpoise (scuba gear) – Australian scuba manufacturer
Powerhead – Specialized firearm used underwater that is fired when in direct contact with the target
Positive pressure breathing – Breathing gas which is at a slightly higher pressure than in the resting lung
Positive pressure breathing apparatus – Equipment in which pressure insude the facepiece is always higher than ambient pressure
Positive pressure open circuit breathing apparatus – Equipment allowing or assisting the user to breath in a hostile environmentPages displaying short descriptions of redirect targets
Potable water diver – Person competent to dive in potable water systems
Potable water diving – Underwater diving in potable water systems
Power inflator – Low pressure gas supply valve for buoyancy compensator
PowerSwim – Diver-powered propulsion device
Pre-dive briefing – Meeting of the dive team to discuss details before the diving operation
Pre-dive checks – Checks done prior to entering the water for a dive
Pressure – Force distributed over an area
Pressure reducing regulator – Pressure control valve that maintains the downstream pressure setting
Pressure reduction regulator – Control valve that reduces and maintains the outlet pressure of a fluid
Pressure swing adsorption – Method of gases separation using selective adsorption under pressure
Pressure-tight zipper – Zip fastener capable of a seal across a gas pressure difference
Pressure transmitter (diving) – Cylinder pressure transducer with wireless transmitter linked to dive computer
Pressure vessel for human occupation – Container to be occupied by one or more people with an internal pressure different from outside
Primary demand valve – The second stage regulator that the diver normally uses
Priz-class deep-submergence rescue vehicle – Russian submersibles
Professional Association of Diving Instructors (
PADI ) – Recreational diver training and certification agency
Professional Divers' Association of Australia – Trade union
Professional diver training – Training of candidates for registration as professional divers
Professional diving , also known as Occupational diving – Underwater diving where divers are paid for their work
Professional Diving Instructors Corporation (
PDIC ) – Recreational diver training and certification agency
Professional scuba diver – Person with skills and knowledge required for occupational diving
Professional Technical and Recreational Diving – Diver certification agency
Protection of Military Remains Act 1986 – UK legislation protecting wreckage of military ships and aircraft
Protection of Wrecks Act 1973 – UK legislation on conservation of shipwrecks
Psychological fitness to dive – Psychological fitness of a person to function safely underwater under pressure
Psychosocial hazard – Occupational hazard to one's psychological well-being
Psychrometric constant – Relation of the partial pressure of water in air to temperature
Public safety diver – Diver working in the public safety sector
Public safety diver training – Training divers for public safety services
Public safety diving – Underwater work done by law enforcement, rescue and search and recovery teams
Pulmonary barotrauma – Lung over-pressure and squeeze injuries
Pulmonary circulation – Part of the circulatory system which carries blood from heart to lungs and back to the heart
Pulmonary edema of immersion – Body fluid in the lungs while immersed
Pulmonary oxygen toxicity – Lung injury due to nlong term exposure to high oxygen levels
Pulmonary volutrauma – Lung injury due to over-expansion
Purge button – Manual activation control of the demand valve
Pyle stop – Type of short deep decompression stops in addition to the standard profile
Pyle, Richard – American ichthyologist and scuba diver
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R-2 Mala-class swimmer delivery vehicle – 2-man wet sub swimmer delivery vehicle class of the Yugoslavian, and later, Croatian, Navies
Rack operator – Member of a surface-supplied diving team who operates the breathing gas panel
Raid on Alexandria (1941) – Italian frogman raid on British warships
Raid on Algiers – Italian frogman raid on Allied ships in Algiers harbour in 1942
Rash guard , also known as Rash vest – Stretch garment for protection from abrasion, UV and stings
Ratchet reel (diving) – Type of reel used by divers to deploy and recover line
Ratio deco – Rule of thumb for estimating a decompression schedule for a given set of breathing gases
Ratio decompression – Rule of thumb for estimating a decompression schedule for a given set of breathing gases
Rawlins, John – Royal Navy officer and pioneer in the field of diving medicine
Rebreather – Portable apparatus to recycle breathing gas
Rebreather Association of International Divers – Recreational diver training and certification agency
Rebreather diver – Scuba diving qualification to use a rebreather
Rebreather diving – Underwater diving using self contained breathing gas recycling apparatus
Rebreather endurance – The duration that a rebreather can adequately supply appropriate breathing gas
Rebreather head-up display – User information interface always in view of the diver
Rebreather loop – Ambient pressure breathing gas circuit
Rebreather scrubber – Component that removes carbon dioxide from exhaled gas
Reclaim helmet – Diving helmet that returns exhaled gas through a hose for recycling
Reclaim regulator – Diving regulator controlling flow of exhaled gas into low pressure exhaust return hose
Reclaim valve – Backpressure regulator controlled relative to ambient pressure for breathing gas recovery
Recompression (disambiguation) – Returning to a state of higher ambient pressure
Recompression chamber – A hyperbaric chamber used to treat divers suffering from decompression illness
Recovery breathing – Brearhing technique used by free divers on surfacing to reduce the risk of surface blackout
Recovery of a convulsing diver – Procedure for rescue of a convulsing scuba diver from underwater
Recovery of an unresponsive diver – Procedure for rescue of a convulsing casualty from underwater
Recreational dive – Underwater dive done for recreational purposes
Recreational Dive Planner – PADI no-decompression dive table also available as a circular slide rule and electronic calculator
Recreational dive sites – Places that divers go to enjoy the underwater environment
Recreational diver certification – Certification as competent to dive to a specified standard
Recreational diver certification agency – Agencies which issue certification for competence in recreational diving skills
Recreational diver impact on reefs – Effects of scuba diving on the underwater environment
Recreational diver training – Training process for people who do not dive at work
Recreational divers – People who engage in underwater diving for entertainment
Recreational diving – Diving for the purpose of leisure and enjoyment, usually when using scuba equipment
Recreational diving fatalities – Deaths occurring during scuba dives
Recreational diving instructor – Person who trains and assesses recreational divers
Recreational diving tourism – Industry based on recreational diver travel
Recreational scuba certification levels – Competence represented by recreational scuba certification
Recreational scuba diving – Diving for leisure and enjoyment while using scuba equipment
Recreational trimix diver – Certification to dive with normoxic trimix with equivalent narcotic depth 80 ft or less
Reduced gradient bubble model – Decompression algorithm
Redundancy (engineering) – Duplication of critical components to increase reliability of a system
Redundant breathing gas supply – Scuba breathing gas reserved for an emergency
Reef – A shoal of rock, coral or other sufficiently coherent material, lying beneath the surface of water
Reef Ball Foundation – Non-profit organization to promote artificial reef building
Reef Check – International NGO for reef conservation
Reef Life Survey (
RLS ) – Marine life monitoring programme based in Hobart, Tasmania
Refresher course – Training to update existing skills and knowledge
Refresher training – Training to update existing skills and knowledge
Refresher training (diving) – Checkout of skills or remedial training to bring skills back up to standard
Regulator freeze – Underwater breathing apparatus malfunction
Regulator freezing – Locking of a diving regulator by ice formation
Regulator icing – Locking of a diving regulator by ice formation
Regulator malfunction – Failure modes for diving regulators
Remotely operated underwater vehicle (
ROUV or ROV ) – A tethered underwater mobile device operated by a remote crew
REMUS (AUV) – Autonomous underwater vehicle seriesPages displaying short descriptions of redirect targets
Repetitive dive – Dive made while outgassing from a previous dive is incomplete
Repex – Repeated exposure to potentially toxic concentrations of oxygen in breathing gas
Rescue bell – Diving bell for submarine rescue
Rescue diver – Recreational scuba certification emphasising emergency response and diver rescue
Rescue Diver – Recreational scuba certification emphasising emergency response and diver rescue
Rescue tether – Short rope with a clip at the end attached to diver's harness to support a casualty in a rescue
Rescue ventilation – Assisted breathing to support life
Reserve gas supply (diving) – Surface breathing gas supply for diving use if main supply is compromised
Reserve valve – Valve isolating access to reserve gas supply
Residual inert gas tissue loading – Gas remaining in the tissues after decompression
Residual nitrogen – Excess nitrogen remaining in body tissues after surfacing from a dive
Residual nitrogen time – Estimate of excess nitrogen remaining in tissues before repetitive dive
Resort diving – Introductory scuba diving experience
Respiration (physiology) – Exchange of gases between environment and tissues
Respiratory exchange ratio – Ratio between the metabolic production of carbon dioxide and the uptake of oxygen
Respiratory gas exchange – Process by which gases diffuse through a biological membrane
Respiratory interface – Facepiece of a breathing apparatus
Respiratory quotient – Ratio of carbon dioxide produced by the body to oxygen consumed by the body
Restriction (diving) – Space through which it is possible to pass with some difficulty
Reverse squeeze – Failure of the Eustachian tubes to open during a reduction in ambient pressure
Rip current – Water current moving away from shore
Risk assessment – Estimation of risk associated with exposure to a given set of hazards
Risk control – Process in which identified risks are reduced or mitigated
Risk management – Identification, evaluation and control of risks
RN Diving Manual – Training and operations manual
Rock bottom gas planning – Scuba gas planning based on a planned dive profile
Rocky reef – Natural reef of rock
Röjdykare – Clearance divers of the Swedish Navy
ROUV – Remotely operated underwater vehicle
ROV KIEL 6000 – Remotely operated vehicle built by Schilling Robotics, Davis, California for scientific tasks
ROV PHOCA – Remotely operated underwater vehicle of the COMANCHE type
ROV Supervisor – A senior ROV pilot appointed to supervise the ROV team
Royal Australian Navy School of Underwater Medicine (
RANSUM ) – Unit based in Sydney, Australia.
Royal Engineers – Engineering arm of the British Army
HMS Royal George (1756)#Salvage attempts – 100-gun first-rate Royal Navy ship of the line (1756) – Early salvage operation using bells and surface supplied divers
Royal Navy ships diver – Category of underwater diver in the Royal Navy
Rubicon Foundation – Non-profit organization for promoting research and information access for underwater diving
Rule of thirds (diving) – Rule of thumb for scuba gas management
Russian commando frogmen – Tactical scuba diving unit
Russian deep submergence rescue vehicle AS-28 – Priz-class deep-submergence rescue vehicle of the Russian Navy
Russian submarine AS-34 – Priz-class deep-submergence rescue vehicle
Russian submarine Losharik – Russian deep-water nuclear submarine
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Safety culture – Attitude, beliefs, perceptions and values that employees share in relation to risks in the workplace
Safety data sheet , also known as Material safety data sheet – Sheet listing work-related hazards
Safety sausage – Inflatable buoy used by a diver at the surface to indicate position to the dive boat
Safety stop – Optional decompression stop to reduce decompression stress
Salt spray aspiration – Inhalation of salt water droplets
Salt water aspiration syndrome – Rare diving disorder caused by inhaling a mist of seawater
Salvage diving – Diving work associated with the recovery of vehicles, cargo and structures
Salvage of the SS Egypt's gold – Recovery of bullion from wreck using an atmospheric pressure observation bell
Salvage operations on HMS Royal George – Early salvage operations using bells and surface supplied divers
Sappers Divers Group – Portuguese Navy's diving unit
Saturation diver – Diver registered as competent for saturation diving
Saturation diving – Diving decompression technique
Saturation diving skills – Skills and procedures required for the safe operation and use of saturation diving equipment
Saturation diving system – Facility for supporting saturation diving projects
Saturation spread – The topside base for saturation diving operations
Saturation system – Diving decompression system
Save Ontario Shipwrecks (
SOS ) – A provincial heritage NGO in Ontario, Canada
S-BRUV – Stereoscopic baited remote underwater video
Science of underwater diving – Scientific concepts that are closely associated with underwater diving
Scientific diver training – Training divers who will be doing scientific work underwater
Scientific diving – Use of diving techniques in the pursuit of scientific knowledge
SCMBA – British military rebreather
Scorpio ROV – Work class remotely operated underwater vehicle
Scottish Sub Aqua Club (
ScotSAC ) – Scottish recreational diver training and certification agency
Screw gate carabiner – Carabiner snap hook with screw lock gate
Scrubber breakthrough – Failure mode in rebreathers when the carbon dioxide scrubber is exhausted
Scrubber endurance – The duration that a rebreather scrubber can adequately remove carbon dioxide
Scuba configuration – The arrangement of self contained breathing apparatus carried by a diver
Scuba contents gauge – Submersible pressure gauge for scuba cylinders
Scuba cylinder valve – Valve controlling flow of breathing gas into and out of a scuba cylinder
Scuba diving – Swimming underwater, breathing gas carried by the diver
Scuba diving fatalities – Deaths occurring while scuba diving or as a consequence of scuba diving
Scuba diving in the Cayman Islands – Recreational diving tourism destination
Scuba Diving International (
SDI ) – Recreational diver training and certification agency
Scuba diving quarry – Disused and flooded quarry repurposed for underwater diving
Scuba diving skills – The skills required to dive safely using self-contained underwater breathing apparatus
Scuba diving therapy – Treatment using scuba diving activities
Scuba diving tourism – Industry based on recreational diver travel
Scuba Educators International (
SEI ) – Recreational diver training and certification agency
Scuba equipment – Equipment needed for scuba diving
Scuba fatalities – Deaths occurring while scuba diving or as a consequence of scuba diving
Scuba finswimming – Underwater sport discipline
Scuba gas blender – Person competent to blend breathing gases for scuba diving
Scuba gas consumption – Breathing gas used while scuba diving
Scuba gas management – Logistical aspects of scuba breathing gas
Scuba gas planning – Estimation of breathing gas mixtures and quantities required for a planned dive profile
Scuba gas reserve – Breathing gas reserved for contingencies
Scuba gear – The equipment used by a scuba diver for diving
Scuba harness – Equipment for supporting a scuba set on a diver
Scuba isolation manifold – Component used to functionally connect scuba cylinders
Scuba manifold – Scuba component used to functionally connect diving cylinders
Scuba mouthpiece – Bite grip breathing interface on demand valve
Scuba orienteering – Underwater compass navigation and speed competition on scuba.
Scuba regulator – Mechanism that controls the pressure of a breathing gas supply for scuba diving
Scuba replacement – Surface-supplied diving where primary and reserve gas supplies are from high-pressure cylinders
Scuba reserve valve – Scuba gas supply valve which is opened to release the gas held in reserve
Scuba Schools International (
SSI ) – Recreational scuba and freediving training and certification agency
Scuba set – Self-contained underwater breathing apparatus
Scuba skills – The skills required to dive safely using a self-contained underwater breathing apparatus.
Scubapro – Brand of scuba diving equipment
SDBA – Special duty oxygen breathing apparatus, a military rebreather.
Seabed mining – Mineral recovery from the bottom of the sea
Seabed tractor – Special purpose class of remotely operated underwater vehicle
Sea Dragon-class ROV – Chinese deep diving work class remotely operated underwater vehicle
Seafox drone – Remotely operated anti-mine marine drone
Seaglider – Deep diving autonomous underwater vehicle for long term missions
SeaKeys – Collaborative marine biodiversity project in South Africa
SEALAB – Experimental underwater habitats developed by the United States Navy
SEAL Delivery Vehicle – Manned wet submersible for deploying naval special forces
Sea level atmospheric pressure – Static pressure exerted by the weight of the atmosphere at sea level
SeaPerch – Remotely operated underwater vehicle educational program
Sea Pole-class bathyscaphe – Chinese bathyscaphe class
Sea Research Society – American nonprofit for marine research
SEAL Delivery Vehicle (
SDV ) – Manned wet submersible for deploying naval special forces
Search and recovery diver – Diver certified as trained in underwater search and recovery
Willard Franklyn Searle – US Navy ocean engineer and developer of diving and salvage equipment and systems
Seasickness , also known as Motion sickness – Motion sickness occurring at sea
Self-reliant diving – Philosophy and practice of diving that does not rely on assistance
Self-sufficient diving – Scuba diving with skill and equipment to manage most contingencies without assistance
Semi-submersible platforms – Marine vessel used in offshore roles wtth good stability and seakeeping
Sentry (AUV) – Autonomous underwater vehicle made by Woods Hole Oceanographic institution
Sewer diving – Diving for maintenance work in sewers
Shadow Divers – Book by Robert Kurson recounting the discovery of a World War II German U-boat wreck
Shallow water blackout – Loss of consciousness at a shallow depth during a dive
Shallow Water Combat Submersible – Manned submersible and a type of swimmer delivery vehicle
Shallow water helmet – Free-flow diving helmet for shallow work
Shallow-water blackout – Loss of consciousness at a shallow depth during a dive
Shallow-water diving helmet – Open-bottom diving helmet held on by weight
Shark baiting – Attracting sharks by chumming the water
Shark cage diving – Diving inside a protective cage to observe sharks in the wild
Shark-proof cage – A metal structure to protect divers and snorkellers from potentially dangerous sharks
Shark River Reef – Artificial reef off New Jersey
Shark tourism – Tourism industry based on viewing wild sharks
Shayetet 13 – Special operations unit of the Israeli Navy
Shearwater Research – Canadian manufacturer of dive computers and rebreather electronics.
Shilling, Charles Wesley – U.S. Navy physician, researcher, and educator
Ships husbandry – Maintenance and upkeep of ships
Ships husbandry diving – Diving related to the maintenance and upkeep of ships
Shot-line , also known as shot line or shotline – Substantial weighted near-vertical line with buoy
Sidemount – Diving equipment configuration where scuba sets are clipped to the diver's sides
Sidemount diver – Scuba certification for using scuba sets clipped to the sides of the harness
Sidemount diving – Diving using equipment configuration where scuba sets are clipped to the diver's sides
Side-mount scuba – Scuba sets carried clipped to the sides of the diver's harness
Side-slung bailout set – Bailout cylinder clipped to the side of the diver's back-mount cylinder harness
Siebe, Augustus – British engineer mostly known for his contributions to diving equipment
Siebe Gorman – British manufacturer of diving equipment and salvage contractor
Siebe Gorman CDBA – Type of diving rebreather used by the Royal Navy
Siebe Gorman Salvus – Industrial rescue and shallow water oxygen rebreather
Signal tube – Inflatable buoy used by a diver at the surface to indicate position to the dive boat
List of signs and symptoms of diving disorders – Evidence of physiological disorders resulting from underwater diving
Silt out – Reduction of underwater visibility by disturbing silt deposits
Silt out , also known as siltout, or silt-out – Reduction of underwater visibility by disturbing silt deposits
Silt screw – A peg for insertion into soft sediment to locate a distance line
Single atmosphere diving suit – Articulated pressure resistant anthropomorphic housing for an underwater diver
Single-hose – Mechanism that reduces pressure of a gas supply and provides it to the diver at ambient pressure
Single-hose diving regulator – Mechanism that reduces pressure of a gas supply and provides it to the diver at ambient pressure
Single point of failure – A part whose failure will disrupt the entire system
The Silent World: A Story of Undersea Discovery and Adventure – Book by Jacques-Yves Cousteau and Frédéric Dumas
Siluro San Bartolomeo – Italian manned torpedo design of late WWII
Single point of failure – A part whose failure will disrupt the entire system
Sinking of MV Conception – 2019 maritime disaster
Sinking of the Rainbow Warrior – 1985 covert attack by French foreign intelligence service on a Greenpeace ship
Sinking ships for wreck diving sites – Scuttling old ships to produce artificial reefs
Sinus squeeze – Barotrauma of the sinuses
Sistema Huautla – Cave system in the southern Mexican state of Oaxaca
Sistema Nohoch Nah Chich – Flooded cave system in Mexico
Sistema Ox Bel Ha – Flooded cave system in Quintana Roo, Mexico
Situation awareness – Adequate perception of environmental elements and external events
Siva (rebreather) – Range of military rebreathers
SJT-class ROUV – Series of Chinese remotely operated underwater vehicles
Skandalopetra diving – Freediving using a stone weight at the end of a rope to the surface
Skindiving (disambiguation)
Sladen Suit – Early British military drysuit
Sling (rigging) – Rope, webbing, wire or chain used to support a load for lifting
Sling cylinder – An independent scuba set carried clipped to the side rings of a scuba diver's harness
Slingshot valve – Dual outlet scuba cylinder valve with Y-shape body
Smith, Gordon – Inventor of KISS diving rebreather, born 1950
Snag-line search – Use of a taut line towed across the search area to catch on the target
Snell's law , also known as Law of refraction – Formula for refraction angles
Snoopy loop , also known as ranger band – Rubber band made from inner tube
Snorkel – Tube for breathing face down at the surface of the water
Snorkel mask – Breathing apparatus for surface swimming
Snorkeling – Swimming while inhaling through a snorkel
Snorkeling vest , also known as snorkelling vest – Peronal buoyancy aid for use while snorkeling
Snuba – Limited depth airline breathing apparatus towed by the diver
Society for Underwater Historical Research – Amateur maritime archaeology organisation in South Australia
Solo diver – SDI recreational diver self-sufficiency certification
Solo diving – Recreational diving without a dive buddy
Solubility – Capacity of a substance to dissolve in a solvent in a homogeneous way
Solution – Homogeneous mixture of a solute and a solvent
Sonar – Acoustic sensing method
Sonic orifice – Orifice undergoing choked flow of a compressible medium
South African Association for Marine Biological Research (
SAAMBR ) – Non profit conservation research organisation based in Durban, SA
South African Department of Employment and Labour – Department of the South African government responsible for matters related to employment
South African Environmental Observation Network (
SAEON ) – A network to perform long-term ecological research in South Africa and surrounding waters
South African Underwater Sports Federation (
SAUSF ) – Official World Underwater Federation representative body in the Republic of South Africa
South Pacific Underwater Medicine Society (
SPUMS ) – Publisher for diving and hyperbaric medicine and physiology
South Pacific Underwater Medical Society Journal – Journal covering underwater and hyperbaric medicine and physiology
Southern African Underwater and Hyperbaric Medical Association (
SAUHMA ) – Special interest group of the Council of the South African Medical Association
SP-350 Denise – French two-person submarine
Spearfisherman (company) – American diving equipment manufacturer
Spearfishing – Hunting for fish using a spear
Speargun – Underwater fishing implement
Special Actions Detachment – Special operations maritime unit of the Portuguese Navy
Special Air Service – Special forces of the British Army
Special Air Service Regiment – Special forces unit of the Australian Army
Special Boat Service – Special forces unit of the Royal Navy
Special Duties Unit – Hong Kong Police tactical unit
Special Forces Command (Turkey) – Turkish special forces group
Special Forces Group (Belgium) – Special forces unit in the Belgian Armed Forces
Special Operations Battalion (Croatia) – Special forces military unit
Special Service Group (Navy) – The special operations force of the Pakistan Navy
Special Warfare Diving and Salvage – Bangladesh Navy special operations force
Speleonaut – Diver propulsion vehicle designed for cave exploration by a disabled diver
Spindle (vehicle) – Ice penetrating two-stage autonomous underwater vehicle
Spiral box search – Search pattern expanding stepwise outward from datum
Spitcock – Valve on diving helmet to let diver spit water on inside of viewport
Sponge diving – Diving to gather natural sponges
Sport (shipwreck) – Tugboat wrecked in Lake Huron
Sport diving (sport) – Underwater sport using recreational open circuit scuba equipment in a swimming pool
SPP-1 underwater pistol – Soviet four-barreled underwater dart pistol
SPUMS – Publisher for diving and hyperbaric medicine and physiology
SPURV – Self propelled underwater research vehicle built in 1957 for the US Navy
SPURV II – Special purpose underwater research vessel built to srudy submarine wakes
Squeeze (diving) – Barotrauma of descent
SRV-300 – Deep-submergence rescue vehicle
Stabilizer jacket – Configuration of diving buoyancy compensator
Stage cylinder – Diving cylinder intended to be collected for use on the return part of a scuba dive
Staged deccompression , also known as Stage decompression – Decompression with stops ad specific depths
Stage drop , also known as Stage-drop – Placing a scuba cylinder at the distance line for planned later use.
Stage rigging (scuba) – Clips, cords and straps on a scuba cylinder to attach it to a diver
Stage set (scuba) – Scuba set to be used during a stage of a dive
Staged decompression – Ascant from dive interrupted by periods at constant depth
Standard diving dress – Copper helmet with rubberised canvas diving suit and weighted boots
Standard diving equipment – Copper helmet with rubberised canvas diving suit and weighted boots
Standard diving helmet – Copper free-flow helmet system used with Standard Diving Dress
Standard helmet – Helmet of standard diving dress
Standard operating procedure – Set of detailed instructions to assist in workplace safety
Standard procedure – A recommend way to do something that is known to be effective and safe
Standby diver , also known as Stand-by diver – Diver who is ready to go to the assistance of the working diver
Standard diving dress – Copper helmet with rubberised canvas diving suit and weighted boots
Standard operating procedure – Set of detailed instructions to assist in workplace safety
Star Canopus diving accident – Fatal offshore diving bell accident in 1978
Static apnea – Stationary diving discipline of holding breath underwater
Stena Seaspread diving accident – Saturation diving bell incident with successful rescue in the North Sea in 1981
Stratification – Layering of a body of water due to density variations
Stress exposure training – Training in a deliberately distracting environment
Striver (bathyscaphe) – Chinese deep submergence vehicle
Struggler (bathyscaphe) – Chinese deep submergence vehicle
Sub-Aqua Association (
SAA ) – British recreational diver training and certification organisation
Submarine emergency gas supply – Breathing gas system installed in submarine for emergency use
Submarine Escape Immersion Equipment – Whole-body exposure suit that allows submariners to escape from a sunken submarine
Submarine escape set – Self contained breathing apparatus providing gas to escape from a submerged submarine
Submarine escape training facility – Facility used for training submariners in methods of escape from a sunken submarine
Submarine Escape Training Facility (Australia) – Shore facility of the Royal Australian Navy
Sub Marine Explorer – Early submarine craft
Submarine pipeline – Pipeline that is laid on the seabed or below it inside a trench
Submarine Products – Former British diving equipment manufacturer and distributor.
Submarine rescue – Rescue of personnel from a disabled submarine
Submarine Rescue Diving Recompression System – Remotely operated vehicle for rescue of personnel from sunken submarines
Submarine rescue ship – Support ship for submarine rescue and deep-sea salvage operations
Submersible pressure gauge – Pressure measuring instrument for underwater service
Subskimmer – Submersible diver propulsion vehicle with inflatable buoyancy for surface use
Subsurface (software) – Creator and lead developer of the Linux kernel (born 1969)Pages displaying short descriptions of redirect targets
Suit squeeze – Barotrauma caused by the folds of a diving suit piching the skin
Superoxide scrubber – Breathing gas scrubber that adds oxygen and removes carbon dioxide
Supersaturation – State of a solution that contains more solute than can be dissolved at equilibrium
Supervised diver – Minimum requirements for a recreational diver to dive in open water under direct supervision
Supervised Diver – Minimum requirements for a recreational diver to dive in open water under direct supervision
Supply lock – Small airlock to transfer supplies between areas of different pressure
Support diver – Recreational diving equivalent of a stand-by diver
Surface blackout – Loss of consciuosness immediately following surfacing of a freediver
Surface decompression – Decompression in a diving chamber out of the water
Surface decompression on oxygen – Staged decompression obligation done in a decompression chamber
Surface interval – The time spent out of the water between dives
Surface marker buoy – Buoy towed by a scuba diver to indicate the diver's position
Surface oriented diving – Underwater diving in which the diver starts and finishes at surface pressure
Surface stand-by diver procedures – Functions of member of a professional diving team
Surface-supplied air diver – Person competent to dive with surface-supplied breathing apparatus
Surface-supplied breathing apparatus – Equipment to supply a diver with breathing gas at ambient pressure from the surface
Surface-supplied diver , also known as Surface supplied diver – Underwater diver breathing gas supplied from the surface
Surface-supplied diving – Underwater diving breathing gas supplied from the surface
Surface-supplied diving equipment – Equipment used specifically for surface supplied diving
Surface-supplied diving procedures – Procedures used in the safe operation and use of surface-supplied diving equipment
Surface-supplied diving skills , also known as Surface supplied diving skills – Skills and procedures required for the safe operation and use of surface-supplied diving equipment
Surface-supplied mixed gas diver – Person competent to dive with mixed gas from a closed bell
Surface tension – Tendency of a liquid surface to shrink to reduce surface area
Surface water searches – Procedures to find objects or persons lost at the surface of a body of water
Surface tension – Tendency of a liquid surface to shrink to reduce surface area
Surfactant – Substance that lowers the surface tension between a liquid and another material
Surfer's ear – Common name for an abnormal bone growth within the external ear canal
Surge (wave action) – The component of wave motion close to and parallel with the bottom
Sustained load cracking – Metallurgical failure mode of cracking under a prolonged static load
Suunto – Finnish manufacturer of compasses, dive computers and sports watches
Swedish Armed Forces Diving and Naval Medicine Centre – Diver education and training; diving medicine research and development
Swimfin – Finlike accessories worn on the feet, used for swimming, snorkeling and diving propulsion
Swimming – Self propulsion of a person through water
Swimming-induced pulmonary edema – Body fluid in the lungs while swimming.
Swim-through – Short underwater tunnel with adequate clearance and obvious exit
Systemic circulation – Portion of the cardiovascular system which transports oxygenated blood away from the heart
Systems technician – Person related to diving systems
T
T1200 Trenching Unit – Remotely operated seabed trenching unit
Tactical Divers Group – Special operations force of the Argentine Navy.
Taifib – Indonesian amphibious reconnaissance unit
Talus cave – Cave formed by rockfall debris
Tank weight – Ballast weight attached to a scuba cylinder
Taravana – Decompression sickness after breath-hold diving
Task loading – Relationship between operator capacity and the accumulated activities that must be done
Teaching method – Principles and methods used by teachers to enable student learning
Team redundancy – System for sharing backup equipment and skill diversity
Technical diver training – Processes to develop skills and knowledge to dive safely for technical diving
Technical diving – Extended scope recreational diving
Technical Diving International (
TDI ) – Technical diver training and certification agency
Technical Extended Range (
TXR ) – Recreational scuba and freediving training and certification agency
Tektite habitat – Undersea laboratory and experimental habitat
Temperate reef – Hard benthic substrate and ecosystems in cool to cold water in middle latitudes
Temperature – Physical quantity of hot and cold
Tension-leg platform – Type of offshore platform used in production of oil or gas
Tesei, Teseo – Italian naval officer and pioneering military diver
Test of pressure – Diagnostic technique to identify decompression sickness
Testing and inspection of diving cylinders – Periodical inspection and testing to revalidate fitness for service
Texas Finswimming Association – Official governing body for competitive and recreational finswimming in Texas
Thalmann algorithm – Mathematical model for diver decompression
Thalmann, Edward D. – American hyperbaric medicine specialist and decompression researcher
Tham Luang cave rescue – 2018 international rescue in Thailand
The Darkness Beckons – History of UK cave diving by Martyn Farr
The Last Dive – Non-fiction book by Bernie Chowdhury about a double wreck diving fatality
Thermal undersuit – Insulating undergarments for use with a dry suit
Therapeutic decompression tables – Planned hyperbaric exposure profiles to treat decompression sickness
Therapeutic recompression – Recompression to reduce symptoms of decompression illness
Thermal balance of the diver – Body temperature regulation in the underwater diver
Thermocline – Thermal layer in a body of water
Thermodynamic decompression model – Early model in which decompression is controlled by volume of gas bubbles forming in tissues
Thermodynamic model of decompression – Early model in which decompression is controlled by volume of gas bubbles forming in tissues
Theseus (AUV) – Large autonomous underwater vehicle for laying fibre-optic cable
The Shaft (sinkhole) – Karst feature in South Australia
The Silent World – 1956 French documentary film co-directed by Jacques Cousteau and Louis Malle
The Silent World: A Story of Undersea Discovery and Adventure – Book by Jacques-Yves Cousteau and Frédéric Dumas
Three bolt equipment – Standard diving dress using three bolts to clamp the helmet bonnet to the corselet
Three Star Diver – Fully trained and experienced recreational dive
Through-water communications – Wireless diver voice communications equipment
Tidal race – Fast-moving tidal flow passing through a constriction, forming waves, eddies and strong currents
Tide – Rise and fall of the sea level under astronomical gravitational influences
Tillman, Albert – American educator and underwater diver
Timeline of diving technology , also known as Timeline of underwater diving technology – Chronological list of notable events in the history of underwater diving equipment
Tissue (biology) – Group of similar cells performing a specific function
Tissue slab decompression model – A diffusion limited series tissue decompression model
Tissue slab diffusion model – Diffusion limited series tissue decompression model
Torricellian chamber – Air space in a cave chamber with pressure below atmospheric
Total Nitrogen Time – Equivalent pressure exposure estimate for a repetitive dive
Touboulic, Pierre-Marie – French engineer, inventor and writer
Tourism on the Great Barrier Reef – Service industry in Australia involving recreational diving
Towboard – Underwater survey equipment used to tow a diver
Transfer under pressure – Moving between pressurised vessels without decompression
Transfer under pressure diving – Surface oriented diving from a closed bell and a chamber for decompression
Travel gas – Gas breathed during the descent part of a dive
Tremie – Equipment for underwater concrete placement
Trial diving – Introductory scuba diving experience
Tribonucleation – Mechanism for creation of microbubbles
Trieste II – US Navy's second bathyscaphe
Triger, Jacques – French geologist who invented the pressurised caisson (1801–1867)
Trim weights (diving) – Diving weights distributed primarily to improve trim
Trimix blender – Person competent to blend trimix breathing gases for scuba diving
Trimix (breathing gas) – Breathing gas consisting of oxygen, helium and nitrogen
Trimix Scuba Association (
TSA ) – Recreational technical scuba training and certification agency
Trongle – Device used on submarines to help swimmers to locate a submerged submarine
Tropical coral reef – Reefs built by warm-water coral species
Try-dive – Supervised diving experience to try out diving or equipment
Turbidity – Cloudiness of a fluid
Turkish Underwater Sports Federation (
TSSF ), also known as Türkiye Sualtı Sporları Federasyonu – Turkish national governing body for underwater sport and lifesaving
Twin bladder buoyancy compensator – Scuba diving buoyancy compensator with redundant air bag
Twin-hose regulator – Scuba regulator with two ambient pressure hoses to the mouthpiece
Type 1 wet bell – Open diving bell without onboard gas panel
Type 2 wet bell – Diving bell with onboard gas panel
Type 904 dive tender – Chinese class of naval diving support vessel
U
Umbilical cable – A cable and/or hose bundle which supplies required consumables to a remote user
Umbilical management , also known as Umbilical management (diving) – Safe handling of the diver's umbilical
Umbilical tending – Management of the supply end of the diver's umbilical
Uncontrolled buoyant ascent – Type of diving accident
Uncontrolled decompression – Unplanned drop in the pressure of a sealed system
Undersea and Hyperbaric Medical Society (
UHMS ) – US based organisation for research and education in hyperbaric physiology and medicine.
Undersea Medical Society – Original name of Undersea and Hyperbaric Medical Society
The Undersea World of Jacques Cousteau – Documentary television series about underwater marine life
Undersuit – Clothing worn under a protective suit
Undertow (water waves) – Return flow below (nearshore) water waves.
Underwater – Aquatic or submarine environment
Underwater acoustic communication – Wireless technique of sending and receiving messages through water
Underwater acoustic positioning system – System for tracking and navigation of underwater vehicles or divers using acoustic signals
Underwater acoustics – Study of the propagation of sound in water
Underwater archaeology – Archaeological techniques practiced at underwater sites
Underwater Bike Race – Annual charity event in North Carolina
Underwater blackout syndrome – Loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive
Underwater breathing apparatus – Equipment which provides breathing gas to an underwater diver
Underwater camera housing – Water and pressure resistant container for camera
Underwater citizen science – The organised collection of underwater data for scientific purposes by volunteers
Underwater computer vision – Subfield of computer vision
Underwater concrete placement – Positioning freshly mixed concrete at an underwater location where it is to set
Underwater construction – Industrial construction in an underwater environment
Underwater Construction Teams – Navy construction battalion underwater construction units
Underwater cutting and welding – Metalworking techniques used by underwater divers
Underwater cycling – Stunt in which a bicycle is ridden under water
Underwater Defence (Turkish Armed Forces) – Special operations unit of the Turkish Navy
Underwater demolition – The deliberate destruction or neutralization of man-made or natural underwater obstacles
Underwater Demolition Command – Special warfare unit of the Greek Navy
Underwater Demolition Team – US Navy special operations group
Underwater diver – Person who descends below the surface to interact with the environment
Underwater diver training – Processes by which people develop the skills and knowledge to dive safely underwater
Underwater divers – People who participate in underwater diving
Underwater diving – Descending below the surface of the water to interact with the environment
Underwater diving environment – The underwater environment to which a diver may be exposed
Underwater diving equipment – Equipment used to facilitate underwater diving
Underwater diving on Guam – Recreational diving tourism destination
Underwater diving terminology , also known as
Underwater diving terms – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Underwater domain awareness – Underwater component of maritime domain awareness
Underwater environment – Aquatic or submarine environment
Underwater exploration – Investigating or traveling around underwater for the purpose of discovery
Underwater Explorers Club – British diving club, now defunct
Underwater firearm – Firearms that can be effectively fired underwater
Underwater football – Underwater team sport using snorkeling equipment and an American football
Underwater habitat – Human habitable underwater enclosure filled with breathable gas
Underwater hockey – Underwater sport of pushing a puck into the opposing goal
Underwater hockey in Australia – History and organisation of the sport in Australia
Underwater hockey in Turkey – History and organisation of the sport in Turkey
Underwater Hockey Wales – Welsh underwater hockey association
Underwater Hockey World Championships – International event for the sport of Underwater Hockey
Underwater ice hockey – Freediving variant of ice hockey played upside-down under the ice
Underwater inspection – Examination of underwater structure and equipment to assess condition
Underwater mining – Any mining activity done underwater
Underwater navigator – Diver competent to navigate in open water by compass or pilotage
Underwater Offence (Turkish Armed Forces) – Special operations Forces of the Turkish Navy
Underwater orienteering – Underwater compass navigation and speed competition on scuba.
Underwater Orienteering World Championships – International sporting competition
Underwater photography – Genre of photography
Underwater photography (sport) – Competitive underwater digital photography on scuba
Underwater Photography World Championships – International event for the sport of underwater photography
Underwater Port Security System – Defense against hostile swimmer incursions
Underwater rescue – Rescue of persons trapped underwater
Underwater rifle – A man-portable, long-barreled firearm which can be fired effectively underwater
Underwater rugby – Underwater team sport
Underwater rugby in Australia – Water sport
Underwater rugby in Colombia – Regional sporting activity
Underwater rugby in the United States – Class of breathhold watersport
Underwater Rugby World Championships – International sporting competition
Underwater search and recovery – Locating and recovering underwater objects
Underwater searches – Techniques for finding underwater targets
Underwater Society of America (
USOA ) – American national representative organization for underwater sport.
Underwater sports – Competitive underwater recreational activities
Underwater sports at the 2013 Bolivarian Games – Finswimming, free-diving and spearfishing events at San Lorenzo island
Underwater survey – Inspection or measurement in or of an underwater environment
Underwater surveying – Inspection or measurement in or of an underwater environment
Underwater target shooting – Breathhold underwater sport of target shooting with a speargun in a swimming pool.
Underwater tending point – Place where the diver's umbilical is restrained or controlled
Underwater vehicle – Vehicle intended to operate underwater
Underwater videographer – Diver trained in the use of video recorders underwater
Underwater videography – Electronic underwater photography concerned with capturing moving images
Underwater visibility – Distance at which an object can be seen through water
Underwater vision – The ability to see objects underwater
Underwater warfare – One of the three operational areas of naval warfare
Underwater work – Work done underwater during diving operations
Underwater wrestling (disambiguation)
Under way – State of a vessel
United Diving Instructors (
UDI ) – Recreational diver training and certification agency
United States Marine Corps Combatant Diver Course – Military diver training for the US Marines
United States Marine Corps Force Reconnaissance – USMC deep reconnaissance unit
United States Marine Corps Reconnaissance Battalions – Reconnaissance assets of Marine Air-Ground Task Force
United States military divers – Underwater divers employed by the US armed forces
United States Navy Experimental Diving Unit (
NEDU ) – The primary source of diving and hyperbaric operational guidance for the US Navy
United States Navy SEALs – U.S. Navy special operations force
United States Navy SEAL selection and training
Universal Referral Program – System to complete recreational scuba training with another instructor
Unmanned diving – Diving for data collection of the environment
Upstream scuba manifold – Manifold connecting cylinders upstream of the valve
Upstream valve – Valve which is opened against the pressure differential
Upwelling – Replacement by deep water moving upwards of surface water driven offshore by wind
URF (Swedish Navy) – Swedish submarine rescue vehicle
U.S. Divers – Manufacterer of scuba diving equipment
User respiratory interface – Facepiece of a breathing apparatus
US Navy decompression models and tables
U.S. Navy Diving Manual (
USNDM ), also known as United States Navy Diving Manual, or US Navy Diving Manual – Training and operations handbook
U.S. Navy Experimental Diving Unit (
USNEDU, NEDU ) – The primary source of diving and hyperbaric operational guidance for the US Navy
Uwatec – Manufacturer of diving equipment
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See also
Activities Competitions Equipment Freedivers Hazards Historical Organisations
Diving disorders Pressure related Oxygen Inert gases Carbon dioxide Breathing gas contaminants
Immersion related
Treatment Personnel Screening Research
Archeological sites Underwater art and artists Engineers and inventors Historical equipment
Military and covert operations Scientific projects Awards and events Incidents
Publications
Manuals Standards and Codes of Practice General non-fiction Research
Dive guides
Training and registration
Surface snorkeling Snorkeling/breath-hold Breath-hold Open Circuit Scuba Rebreather Sports governing organisations and federations Competitions
Pioneers of diving Underwater scientists archaeologists and environmentalists Scuba record holders Underwater filmmakers and presenters Underwater photographers Underwater explorers
Aquanauts Writers and journalists Rescuers Frogmen Commercial salvors