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

• Rule 1 : Application
• Rule 2 : Responsibility
• Rule 3 : General Definitions

Part B – Steering and Sailing Rules

Section I – Conduct of Vessels in any Condition of Visibility

• 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
• 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

• Rule 19 : 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

The International Navigation Rules do not confer upon any vessel the right of way however, certain vessels in sight of each other are responsible to keep out of the way of others. Usually, power-driven vessels are to keep out of the way of a vessel not under command or restricted in her ability to maneuver, sailing vessels or a vessel engaged in fishing. However, some exceptions exist when they themselves are not in command or restricted in her ability to maneuver (Rule 18), overtaking another vessel (Rule 13), are navigating a narrow channel or fairway (Rule 9), and other less explicit circumstances.

Navigation Rules should be regarded as a code of conduct and not a bill of rights. They do not confer rights or privileges, but impose the duty to either give-way or stand-on, dependent on the circumstances. What is important is not so much what things are, i.e. sailing vessel, operational, etc., but how to avoid collisions, e.g. although under sail yet able to be propelled by machinery, obtaining an early warning by radar, etc. Understand, the Rules are in place to prevent collisions not to define nautical terms or to be subjected to strict interpretation.

Finally, all this said, the ordinary practice of seamen requires precaution under all conditions and circumstances and not strict adherence to the rules or any other practice. Although strict adherence may not always be prudent, the Rules are very precise in stating that nothing shall exonerate any vessel, or the owner, master or crew thereof, from the consequences of any neglect (Rule 2). Neglect, among other things, could be not maintaining a proper look-out (Rule 5), use of improper speed (Rule 6), not taking the appropriate actions to determine and avoid collision [Rules 7 & Rule 8] or completely ignoring your responsibilities under the Rules.