The full text of the regulations is available in Wikisource and in numerous on-line alternatives. Each major part and section here is linked to the appropriate text. To avoid meaningless repetitions of the same reference the text is referenced here and at the end of this section only. [1]
The first part defines how the rules are to be applied.
The rules apply to the "high seas" and all navigable waters connected to them. However Governments are able set rules for men-of-war and for waters within their jurisdiction. Governments may also exempt vessels of "special construction" from parts of the rules.
All those owning or working on vessels are responsible for keeping the rules and applying them according to the circumstances of the case. The rule accepts that departure from the rules may be necessary to "avoid immediate danger".
The rule defines some terms. Less obvious terms are that a "sailing vessel" is only a sailing vessel if she is not also using power; a fishing boat is only such when using large nets (not rod-and-line); a "vessel not under command" is one unable to manoeuvre; and "underway" means not anchored or made fast, even if not actually moving. There is a list of examples of vessels which are "restricted in her ability to manoeuvre" including working with buoys, pipelines, dredging and replenishing at sea.
This part covers the heart of the rules: who gives way to whom and how in a variety of circumstances.
The first section covers the basics of the rules. Later sections deal with good visibility when vessels can see each other and then with poor visibility when they can't.
The rule simply repeats that the section applies in all conditions of visibility.
The rule mandates that all vessels must keep a look out by all available means, this includes both visual and electronic.
A safe speed is one where vessels can take action or stop to avoid a collision. Pointers are given including: visibility, other vessels, wind, currents, navigation hazards and draught. Vessels are warned about the limitations of radar in detecting small vessels and debris in various sea conditions.
Guidelines on assessing if a risk of collision exists.
The rule requires a vessel taking action to avoid a collision to do so in plenty of time and in an obvious manner. The action may be a change of course or of speed and must be apparent to the other vessel. In any case, all vessels remain obliged to comply with the rules to avoid a collision.
The rule does not define what is a narrow channel but within a narrow channel ships must try to keep to the starboard (right hand side) of the channel. Small boats and sailing vessels must keep out of the way of large vessels which are constrained by the narrowness of the channel. Fishing boats must keep out of the way of all craft on passage, as must vessels crossing the channel. Overtaking is permitted, but sound signals may be required (see rule 34) as they are when approaching blind bends. Vessels should not anchor in narrow channels.
Rule 10 is quite complicated and relates to one-way systems set up in areas of high traffic. Vessels must still abide by all other rules.
Larger vessels on a through passage enter and leave the traffic separation scheme (TSS) at its ends only. Smaller vessels generally keep inshore of the TSS lanes, as may large vessels when travelling to and from destinations alongside the TSS (sections (d)(i) and (ii)). Any vessel crossing the TSS must do so at right angles. If joining or leaving part way along a vessel must do so at "as small an angle to the general direction of traffic flow as practicable".
Fishing vessels, small craft and sailing vessels must not impede traffic using the TSS. A vessel restricted in her ability to manoeuvre is generally exempt from this rule.
Merely states that this section relates to vessels in sight of each other.
When two sailing vessels are approaching each other it is the wind direction which decides who has to keep out of the way. If the wind is on a different side of each vessel then the one with the wind to port (ie coming from the left) keeps clear of the other. If however the wind is on the same side of both vessels, then the vessel that is upwind keeps clear. If a vessel has the wind on the port and sees another vessel upwind of her, but cannot determine which side the wind is on the other vessel, then she must keep out of the way. The rule gives guidance that the wind is assumed to come from the side opposite to the way the mainsail is carried.
The rule is simple, an overtaking vessel of any type must keep clear of the other vessel until she is "finally past and clear". The rule defines in detail what is meant by overtaking and in the case of doubt requires vessels assume that they are.
This is the standard "keep right" rule for power driven vessels. Turn to starboard (right) and leave the other vessel on your port (left).
When two power driven vessels are crossing, the one who can see the other to the starboard (right) is called the "give-way" vessel and must keep out of the way of the other vessel. Normally this is by turning to starboard and passing behind. The other vessel is called the "stand-on" vessel and should maintain course and speed.
The give-way vessel has to keep out of the way of the other vessel and should take "early and substantial" action to make it clear she is keeping out of the way.
The rule instructs the stand-on vessel to maintain her course and speed unless the give-way vessel fails to take appropriate action. In that case the stand-on vessel must take appropriate action to avoid a collision. If a stand-on vessel does take such action, she should try to avoid turning to port since to do so increases the chance of a collision.
Except for narrow channels (rule 9), traffic separation schemes (rule 10) and overtaking (rule 13) the rule establishes a precedence:
A higher numbered vessel must keep out of the way of a lower numbered vessel.
The rule then establishes a few special cases. Any vessel other than case 1 and 2 must keep out of the way of a vessel "constrained by her draught" which is showing the appropriate signal according to rule 28. Essentially, big ships need to keep to the deep water channel and cannot avoid smaller vessels, so small vessels have to keep out of the way, regardless of the precedence. The other special cases are seaplanes (including flying boats) and WIG craft (those flying just above the surface). These two cases must keep out of the way of all other craft.
The rule requires vessels to proceed with due caution when visibility is reduced. Vessels need to slow down and be prepared to manoeuvre. If a vessel hears a fog signal forward of her she must slow right down and if necessary stop. There are also rules for when a vessel only detects another by radar alone, essentially it becomes her responsibility, the other vessel may not have radar.
Vessels exhibit distinctive lights to indicate what sort of vessel they are and in which direction they are going. During daylight they display shaped objects to show what they are doing.
The rule requires lights to be used from dusk to dawn and in reduced visibility, and may be used during daylight, whatever the weather. Other lights must not be exhibited if they could cause confusion. Shapes must be used during daylight.
The types of light and the arcs of visibility are defined.
Lights must be visible for certain minimum ranges depending upon the light type and the vessel size.
Power driven vessels exhibit port and starboard lights, a forward facing mast head light and a sternlight. Large vessels exhibit a second masthead light. Very small vessels may exhibit less lights.
Towing vessels exhibit two or three masthead lights and a diamond shape. The tow is also lit. Rigid push-tows are list as for a single vessel.
Sailing vessels exhibit port, starboard and stern lights. A sailing vessel may also exhibit a red light over a green light. Small sailing vessels exhibit proportionately less lights and a vessel under oars does the same or else a single white light. By day a sailing vessel using her engine exhibits a cone pointing downwards.
The rules defines a whistle, a short blast (about 1 second) and a prolonged blast (4 to 6 seconds).
The following sound signals are used when vessels are in sight of each other:
Lights may be used in a similar way to supplement these signals.
Vessels use sound signals where the visibility is restricted by both day or night. Vessels near an area of restricted visibility must also make the signals so that they will be heard within the area.
Vessels cannot use sound sound or light signals that:
to attract attention. Any other sound or light signal can be used though strobes and revolving lights should be avoided.
The rule refers the reader to the annexe.
Vessels constructed or under construction prior to the regulations coming into force are granted certain exemptions. The current rules came into force in 1972.
These three rules define the auditing procedure that the IMO carries out to check that countries are following the code. They do not appear in the 1972 text, but are included in the amended 2016 text.
The annexe gives technical details on the type and positioning of the various lights and shapes.
Three sections describe:
The annexe gives technical details ( frequency, power etc) of whistles, bells and gongs.
The final annexe lists distress signals and regulates their use. For speed of reference this annexe is quoted in its entirety:
1. The following signals, used or exhibited either together or separately, indicate distress and need of assistance:
2. The use or exhibition of any of the foregoing signals except for the purpose of indicating distress and need of assistance and the use of other signals which may be confused with any of the above signals is prohibited.
3. Attention is drawn to the relevant sections of the International Code of Signals, the Merchant Ship Search and Rescue Manual, Annex III and the following signals:
The full text of the regulations is available in Wikisource and in numerous on-line alternatives. Each major part and section here is linked to the appropriate text. To avoid meaningless repetitions of the same reference the text is referenced here and at the end of this section only. [1]
The first part defines how the rules are to be applied.
The rules apply to the "high seas" and all navigable waters connected to them. However Governments are able set rules for men-of-war and for waters within their jurisdiction. Governments may also exempt vessels of "special construction" from parts of the rules.
All those owning or working on vessels are responsible for keeping the rules and applying them according to the circumstances of the case. The rule accepts that departure from the rules may be necessary to "avoid immediate danger".
The rule defines some terms. Less obvious terms are that a "sailing vessel" is only a sailing vessel if she is not also using power; a fishing boat is only such when using large nets (not rod-and-line); a "vessel not under command" is one unable to manoeuvre; and "underway" means not anchored or made fast, even if not actually moving. There is a list of examples of vessels which are "restricted in her ability to manoeuvre" including working with buoys, pipelines, dredging and replenishing at sea.
This part covers the heart of the rules: who gives way to whom and how in a variety of circumstances.
The first section covers the basics of the rules. Later sections deal with good visibility when vessels can see each other and then with poor visibility when they can't.
The rule simply repeats that the section applies in all conditions of visibility.
The rule mandates that all vessels must keep a look out by all available means, this includes both visual and electronic.
A safe speed is one where vessels can take action or stop to avoid a collision. Pointers are given including: visibility, other vessels, wind, currents, navigation hazards and draught. Vessels are warned about the limitations of radar in detecting small vessels and debris in various sea conditions.
Guidelines on assessing if a risk of collision exists.
The rule requires a vessel taking action to avoid a collision to do so in plenty of time and in an obvious manner. The action may be a change of course or of speed and must be apparent to the other vessel. In any case, all vessels remain obliged to comply with the rules to avoid a collision.
The rule does not define what is a narrow channel but within a narrow channel ships must try to keep to the starboard (right hand side) of the channel. Small boats and sailing vessels must keep out of the way of large vessels which are constrained by the narrowness of the channel. Fishing boats must keep out of the way of all craft on passage, as must vessels crossing the channel. Overtaking is permitted, but sound signals may be required (see rule 34) as they are when approaching blind bends. Vessels should not anchor in narrow channels.
Rule 10 is quite complicated and relates to one-way systems set up in areas of high traffic. Vessels must still abide by all other rules.
Larger vessels on a through passage enter and leave the traffic separation scheme (TSS) at its ends only. Smaller vessels generally keep inshore of the TSS lanes, as may large vessels when travelling to and from destinations alongside the TSS (sections (d)(i) and (ii)). Any vessel crossing the TSS must do so at right angles. If joining or leaving part way along a vessel must do so at "as small an angle to the general direction of traffic flow as practicable".
Fishing vessels, small craft and sailing vessels must not impede traffic using the TSS. A vessel restricted in her ability to manoeuvre is generally exempt from this rule.
Merely states that this section relates to vessels in sight of each other.
When two sailing vessels are approaching each other it is the wind direction which decides who has to keep out of the way. If the wind is on a different side of each vessel then the one with the wind to port (ie coming from the left) keeps clear of the other. If however the wind is on the same side of both vessels, then the vessel that is upwind keeps clear. If a vessel has the wind on the port and sees another vessel upwind of her, but cannot determine which side the wind is on the other vessel, then she must keep out of the way. The rule gives guidance that the wind is assumed to come from the side opposite to the way the mainsail is carried.
The rule is simple, an overtaking vessel of any type must keep clear of the other vessel until she is "finally past and clear". The rule defines in detail what is meant by overtaking and in the case of doubt requires vessels assume that they are.
This is the standard "keep right" rule for power driven vessels. Turn to starboard (right) and leave the other vessel on your port (left).
When two power driven vessels are crossing, the one who can see the other to the starboard (right) is called the "give-way" vessel and must keep out of the way of the other vessel. Normally this is by turning to starboard and passing behind. The other vessel is called the "stand-on" vessel and should maintain course and speed.
The give-way vessel has to keep out of the way of the other vessel and should take "early and substantial" action to make it clear she is keeping out of the way.
The rule instructs the stand-on vessel to maintain her course and speed unless the give-way vessel fails to take appropriate action. In that case the stand-on vessel must take appropriate action to avoid a collision. If a stand-on vessel does take such action, she should try to avoid turning to port since to do so increases the chance of a collision.
Except for narrow channels (rule 9), traffic separation schemes (rule 10) and overtaking (rule 13) the rule establishes a precedence:
A higher numbered vessel must keep out of the way of a lower numbered vessel.
The rule then establishes a few special cases. Any vessel other than case 1 and 2 must keep out of the way of a vessel "constrained by her draught" which is showing the appropriate signal according to rule 28. Essentially, big ships need to keep to the deep water channel and cannot avoid smaller vessels, so small vessels have to keep out of the way, regardless of the precedence. The other special cases are seaplanes (including flying boats) and WIG craft (those flying just above the surface). These two cases must keep out of the way of all other craft.
The rule requires vessels to proceed with due caution when visibility is reduced. Vessels need to slow down and be prepared to manoeuvre. If a vessel hears a fog signal forward of her she must slow right down and if necessary stop. There are also rules for when a vessel only detects another by radar alone, essentially it becomes her responsibility, the other vessel may not have radar.
Vessels exhibit distinctive lights to indicate what sort of vessel they are and in which direction they are going. During daylight they display shaped objects to show what they are doing.
The rule requires lights to be used from dusk to dawn and in reduced visibility, and may be used during daylight, whatever the weather. Other lights must not be exhibited if they could cause confusion. Shapes must be used during daylight.
The types of light and the arcs of visibility are defined.
Lights must be visible for certain minimum ranges depending upon the light type and the vessel size.
Power driven vessels exhibit port and starboard lights, a forward facing mast head light and a sternlight. Large vessels exhibit a second masthead light. Very small vessels may exhibit less lights.
Towing vessels exhibit two or three masthead lights and a diamond shape. The tow is also lit. Rigid push-tows are list as for a single vessel.
Sailing vessels exhibit port, starboard and stern lights. A sailing vessel may also exhibit a red light over a green light. Small sailing vessels exhibit proportionately less lights and a vessel under oars does the same or else a single white light. By day a sailing vessel using her engine exhibits a cone pointing downwards.
The rules defines a whistle, a short blast (about 1 second) and a prolonged blast (4 to 6 seconds).
The following sound signals are used when vessels are in sight of each other:
Lights may be used in a similar way to supplement these signals.
Vessels use sound signals where the visibility is restricted by both day or night. Vessels near an area of restricted visibility must also make the signals so that they will be heard within the area.
Vessels cannot use sound sound or light signals that:
to attract attention. Any other sound or light signal can be used though strobes and revolving lights should be avoided.
The rule refers the reader to the annexe.
Vessels constructed or under construction prior to the regulations coming into force are granted certain exemptions. The current rules came into force in 1972.
These three rules define the auditing procedure that the IMO carries out to check that countries are following the code. They do not appear in the 1972 text, but are included in the amended 2016 text.
The annexe gives technical details on the type and positioning of the various lights and shapes.
Three sections describe:
The annexe gives technical details ( frequency, power etc) of whistles, bells and gongs.
The final annexe lists distress signals and regulates their use. For speed of reference this annexe is quoted in its entirety:
1. The following signals, used or exhibited either together or separately, indicate distress and need of assistance:
2. The use or exhibition of any of the foregoing signals except for the purpose of indicating distress and need of assistance and the use of other signals which may be confused with any of the above signals is prohibited.
3. Attention is drawn to the relevant sections of the International Code of Signals, the Merchant Ship Search and Rescue Manual, Annex III and the following signals: