An underwater firearm is a
firearm designed for use
underwater. Underwater firearms or
needleguns usually fire
flechettes or spear-like bolts instead of standard bullets. These may be fired by pressurised gas.[citation needed]
History
This section needs expansion. You can help by
adding to it. (May 2018)
Underwater firearms were first developed in the 1960s during the
Cold War as a way to arm
combat divers.
Design
Because standard bullet
ammunition does not work well underwater, underwater firearms commonly fire
flechettes instead of standard bullets.
The barrels of underwater pistols are typically not
rifled. Rather, the fired projectile maintains its
ballistic trajectory underwater by
hydrodynamic effects. The lack of rifling renders these weapons relatively inaccurate when fired out of water. Underwater rifles are more powerful than underwater pistols and more accurate out of water, but underwater pistols can be manipulated more easily underwater.
Among the many engineering challenges in designing underwater firearms is that of developing a weapon which can be effective both underwater and out of water. The
ASM-DT amphibious rifle is an early example of such a weapon. First fielded by the
Russian special forces in 2000, the folding-stock ASM-DT amphibious rifle is capable of firing two kinds of ammunition, both of 5.45 mm
caliber:
5.45×39mm rifle
cartridge (7N6 enhanced penetration variant) for above water use
5.45×39mm MGTS variant for underwater use. The projectile in this case is a steel dart, 120 mm (4.7 in) in length.[1]
When used against underwater targets, an underwater firearm may have a longer range and more penetrating power than
spearguns. This is useful in such situations as shooting an underwater intruder where the projectile may have to first penetrate a reinforced
dry suit, or a protective
helmet (whether air-holding or not), or a thick tough part of their
breathing set and its
harness, or the plastic casing or transparent cover of a
small underwater vehicle.
Supercavitating ammunition
Supercavitating ammunition that functions better underwater has been developed by Defence & Security Group (DSG), a Norwegian company. The Multi-Environment Ammunition (MEA) series supercavitating rifle ammunition, developed and marketed by DSG, is anticipated to be useful for certain
special operations, including
underwater warfare. These include defensive applications such as diver protection, and offensive applications such as neutralizing enemy divers,
VBSS (visit, board, search, and seizure) operations,
MIO (maritime interception operations),
GOPLATS (Gas and oil platform)
boarding operations, speedboat interdiction and neutralization,
anti-submarine warfare, anti-
torpedo operations, and certain counter-
piracy operations.[2]
The ballistic characteristics of MEA series ammunition allows the user to fire at an underwater target from above the water, an above-the-water target from underwater, or an underwater target from underwater. This ammunition allows the user to fire from above the surface into the water at a very low
angle of incidence—in some cases as low as two degrees—without
ricochet. After entering the water, the bullet will continue its original trajectory. The user, when aiming the gun, needs to compensate for the
refractive index of the water (roughly 1.333 for fresh water at 20 °C (68 °F)).[2]
MEA series supercavitating ammunition is currently available in the following calibers:[2]
5.56×45mm NATO (accurate range of 15 m (49 ft) underwater)
7.62×51mm NATO (accurate range of 25 m (82 ft) underwater)
The underwater capabilities of MEA series
supercavitating ammunition allow it to be used for
unmanned underwater vehicle (UUV) applications. The armed UUVs can be used in both offensive and defensive underwater warfare operations. Using the .50 BMG supercavitating cartridge, an armed UUV can potentially destroy steel-hulled underwater objects from a distance of 60 m (200 ft), or could potentially hit a target 1,000 m (3,300 ft) in the air from a location 5 m (16 ft) below the surface.[2]
The Lancejet (an underwater variant of the
Gyrojet manufactured by MB Associates) was once considered for use by the United States military, but it was removed from consideration due to its inaccuracy under field testing conditions.[citation needed] (For other meanings see
Lancejet.)
An underwater firearm is a
firearm designed for use
underwater. Underwater firearms or
needleguns usually fire
flechettes or spear-like bolts instead of standard bullets. These may be fired by pressurised gas.[citation needed]
History
This section needs expansion. You can help by
adding to it. (May 2018)
Underwater firearms were first developed in the 1960s during the
Cold War as a way to arm
combat divers.
Design
Because standard bullet
ammunition does not work well underwater, underwater firearms commonly fire
flechettes instead of standard bullets.
The barrels of underwater pistols are typically not
rifled. Rather, the fired projectile maintains its
ballistic trajectory underwater by
hydrodynamic effects. The lack of rifling renders these weapons relatively inaccurate when fired out of water. Underwater rifles are more powerful than underwater pistols and more accurate out of water, but underwater pistols can be manipulated more easily underwater.
Among the many engineering challenges in designing underwater firearms is that of developing a weapon which can be effective both underwater and out of water. The
ASM-DT amphibious rifle is an early example of such a weapon. First fielded by the
Russian special forces in 2000, the folding-stock ASM-DT amphibious rifle is capable of firing two kinds of ammunition, both of 5.45 mm
caliber:
5.45×39mm rifle
cartridge (7N6 enhanced penetration variant) for above water use
5.45×39mm MGTS variant for underwater use. The projectile in this case is a steel dart, 120 mm (4.7 in) in length.[1]
When used against underwater targets, an underwater firearm may have a longer range and more penetrating power than
spearguns. This is useful in such situations as shooting an underwater intruder where the projectile may have to first penetrate a reinforced
dry suit, or a protective
helmet (whether air-holding or not), or a thick tough part of their
breathing set and its
harness, or the plastic casing or transparent cover of a
small underwater vehicle.
Supercavitating ammunition
Supercavitating ammunition that functions better underwater has been developed by Defence & Security Group (DSG), a Norwegian company. The Multi-Environment Ammunition (MEA) series supercavitating rifle ammunition, developed and marketed by DSG, is anticipated to be useful for certain
special operations, including
underwater warfare. These include defensive applications such as diver protection, and offensive applications such as neutralizing enemy divers,
VBSS (visit, board, search, and seizure) operations,
MIO (maritime interception operations),
GOPLATS (Gas and oil platform)
boarding operations, speedboat interdiction and neutralization,
anti-submarine warfare, anti-
torpedo operations, and certain counter-
piracy operations.[2]
The ballistic characteristics of MEA series ammunition allows the user to fire at an underwater target from above the water, an above-the-water target from underwater, or an underwater target from underwater. This ammunition allows the user to fire from above the surface into the water at a very low
angle of incidence—in some cases as low as two degrees—without
ricochet. After entering the water, the bullet will continue its original trajectory. The user, when aiming the gun, needs to compensate for the
refractive index of the water (roughly 1.333 for fresh water at 20 °C (68 °F)).[2]
MEA series supercavitating ammunition is currently available in the following calibers:[2]
5.56×45mm NATO (accurate range of 15 m (49 ft) underwater)
7.62×51mm NATO (accurate range of 25 m (82 ft) underwater)
The underwater capabilities of MEA series
supercavitating ammunition allow it to be used for
unmanned underwater vehicle (UUV) applications. The armed UUVs can be used in both offensive and defensive underwater warfare operations. Using the .50 BMG supercavitating cartridge, an armed UUV can potentially destroy steel-hulled underwater objects from a distance of 60 m (200 ft), or could potentially hit a target 1,000 m (3,300 ft) in the air from a location 5 m (16 ft) below the surface.[2]
The Lancejet (an underwater variant of the
Gyrojet manufactured by MB Associates) was once considered for use by the United States military, but it was removed from consideration due to its inaccuracy under field testing conditions.[citation needed] (For other meanings see
Lancejet.)