International Regulations for Avoiding Collisions at Sea or IRPCS. The rules are specified in great detail in the regulations and the serious student is encouraged to seek the definitive document. Certain individuals are legally required to carry or possess a copy of the rules, such as the owners and/or operators of certain vessels. These legal requirements vary by jurisdiction. Consult the appropriate maritime authorities for each jurisdiction. Any individual subject to such requirements should obtain a complete, official copy from a government or official source. However, the rules are summarized below.
Part A - General
Part B - Steering and Sailing Rules
- Rule 4 : Application
- Rule 5 : Look-out
- Rule 6 : Safe Speed
- Rule 7 : Risk of Collision
- Rule 8 : Action to Avoid Collision
Rule 9 : Narrow Channels
(a) A vessel proceeding along the course of a narrow channel or fairway shall keep as near to the outer limit of the channel or fairway which lies on her starboard side as is safe and practicable.
(b) A vessel of less than 20 meters in length or a sailing vessel shall not impede the passage of a vessel which can safely navigate only within a narrow channel or fairway.
(c) A vessel engaged in fishing shall not impede the passage of any other vessel navigating within a narrow passage or fairway.
(d) A vessel shall not cross a narrow passage or fairway if such crossing impedes the passage of a vessel which can safely navigate only within such channel or fairway. The latter vessel may use the sound signal prescribed in Rule 34(d) if in doubt as to the intention of the crossing vessel.
(i) In a narrow channel or fairway when overtaking can take place only when the vessel to be overtaken has to take action to permit safe passing, the vessel intending to overtake shall indicate her intention by sounding the appropriate signal prescribed in Rule 34(c)(i). The vessel to be overtaken shall, if in agreement, sound the appropriate signal prescribed in Rule 34(c)(ii) and take steps to permit safe passing. If in doubt she may sound the signals prescribed in Rule 34(d).
(ii) This rule does not relieve the overtaking vessel of her obligation under Rule 13.
(f) A vessel nearing a bend or an area of a narrow channel or fairway where other vessels may be obscured by an intervening obstruction shall navigate with particular alertness and caution and shall sound the appropriate signal prescribed in Rule 34(e).
(g) Any vessel shall, if the circumstances of the case admit, avoid anchoring in a narrow channel.
- Rule 10 : Traffic Separation Schemes
Section II - Conduct of Vessels in Sight of One Another
- Rule 11 : Application
- Rule 12 : Sailing Vessels
- Rule 13 : Overtaking
- Rule 14 : Head-on Situation
- Rule 15 : Crossing Situation
- Rule 16 : Action by Give-way Vessel
- Rule 17 : Action by Stand-on Vessel
- Rule 18 : Responsibilities Between Vessels
Section III - Conduct of Vessels in Restricted Visibility
Part C - Lights and Shapes
- Rule 20 : Application
- Rule 21 : Definitions
- Rule 22 : Visibility of Lights
- Rule 23 : power driven Vessels Underway
- Rule 24 : Towing and Pushing
- Rule 25 : Sailing Vessels Underway and Vessels Under Oars
- Rule 26 : Fishing Vessels
- Rule 27 : Vessels Not Under Command or Restricted in Their Ability to Maneuver
- Rule 28 : Vessels Constrained by their Draft
- Rule 29 : Pilot Vessels
- Rule 30 : Anchored Vessels and Vessels Aground
- Rule 31 : Seaplanes
Part D - Sound and Light Signals
- Rule 32 : Definitions
- Rule 33 : Equipment for Sound Signals
- Rule 34 : Maneuvering and Warning Signals
- Rule 35 : Sound Signals in Restricted Visibility
- Rule 36 : Signals to Attract Attention
- Rule 37 : Distress Signals
Part E - Exemptions
- Rule 38 : Exemptions