The COLREG rules, at a glance
The Rules of the Road come in numbered rules. Here they are in one place: Part B says who keeps out of whose way, Part C describes the lights and shapes ships are recognised by, and Part D covers the sound signals, down to the signals of distress. Every rule links to its home on this site: the full rule page, the vessel type card or the sound signals page.
Part B: Steering and Sailing Rules Rules 4-19
- 4 Application Rules in this Section apply to any condition of visibility. Give-way rules hub →
- 5 Look-out A look-out is more than watching ahead of the bow: it covers sight, hearing, radar and every other means available in the situation. Full rule page →
- 6 Safe Speed There is no single safe number of knots: safe speed is always a function of the conditions. Full rule page →
- 7 Risk of Collision No appreciable change in the compass bearing of an approaching vessel means you assume risk of collision exists. Confirm the assessment with successive bearings, the change of range and systematic radar observation. Full rule page →
- 8 Action to Avoid Collision The manoeuvre is to be bold, made early and readable for the other vessel, both visually and on radar. Full rule page →
- 9 Narrow Channels Keep as near to the starboard outer limit of the channel or fairway as is safe and practicable. Full rule page →
- 10 Traffic Separation Schemes A TSS is a motorway at sea: you follow your lane, in the general direction of traffic flow. Full rule page →
- 11 Application Rules in this section apply to vessels in sight of one another. Give-way rules hub →
- 12 Sailing Vessels Different tacks: the vessel with the wind on the port side gives way. Full rule page →
- 13 Overtaking Overtaking means giving way. Always, whatever the type of vessel (it beats the Rule 18 ladder). Full rule page →
- 14 Head-on Situation Head-on: BOTH vessels alter course to starboard and pass port to port. Full rule page →
- 15 Crossing Situation She is on your starboard side: you give way. You are on hers: she gives way. Full rule page →
- 16 Action by Give-way Vessel You are giving way: do it early and boldly, so the other bridge has no doubts. Full rule page →
- 17 Action by Stand-on Vessel You are the vessel that keeps her course and speed. Your predictability is what lets the give-way vessel plan a proper manoeuvre. Full rule page →
- 18 Responsibilities Between Vessels Rule 18 is an approximate hierarchy of duties: a power-driven vessel keeps out of the way of sailing vessels, vessels fishing, vessels restricted in their ability to manoeuvre and vessels not under command. Full rule page →
- 19 Conduct of Vessels in Restricted Visibility When vessels are not in sight of one another, the give-way and stand-on roles of Rules 12-18 do not exist. Full rule page →
Part C: Lights and Shapes Rules 20-31
- 20 Application When and in what conditions the lights and shapes are shown. The learning path (step 0) →
- 21 Definitions Colours and sectors: masthead 225°, sidelights 112.5° each, sternlight 135°. The learning path (step 0) →
- 22 Visibility of Lights The minimum visibility ranges of the lights depend on the length of the vessel. The learning path (step 0) →
- 23 Power-driven Vessels Underway Masthead, side and stern lights of a power-driven vessel underway. Vessel type card →
- 24 Towing and Pushing The lights of the towing vessel and the tow, a diamond for a long tow. Vessel type card →
- 25 Sailing Vessels Underway Sidelights and a sternlight; optionally red over green at the masthead. Vessel type card →
- 26 Fishing Vessels Trawling: green over white. Other fishing: red over white. Vessel type card →
- 27 Vessels Not Under Command or Restricted in Their Ability to Manoeuvre Two reds (not under command) or red-white-red (restricted in ability to manoeuvre). Vessel type card →
- 28 Vessels Constrained by Their Draught Three red lights in a vertical line; by day a cylinder. Vessel type card →
- 29 Pilot Vessels White over red at the masthead when a pilot vessel is on duty. Vessel type card →
- 30 Anchored Vessels and Vessels Aground White anchor lights; aground adds two reds in a vertical line. Vessel type card →
- 31 Seaplanes A seaplane shows lights as close as possible to those required. The learning path (step 0) →
Part D: Sound and Light Signals Rules 32-37
- 32 Definitions A short blast lasts about 1 second, a prolonged one 4 to 6. Sound signals page →
- 33 Equipment for Sound Signals A whistle from 12 m, a bell from 20 m, a gong from 100 m of length. Sound signals page →
- 34 Manoeuvring and Warning Signals One short to starboard, two to port, three astern; five means doubt. Sound signals page →
- 35 Sound Signals in Restricted Visibility The identity signals in fog, at intervals of not more than 2 minutes. Sound signals page →
- 36 Signals to Attract Attention You may attract attention with light or sound, as long as it cannot be mistaken for another signal. Attention signals →
- 37 Distress Signals The Annex IV signals: SOS, Mayday, red rockets, flames on the vessel. Distress signals →
The index covers Parts B, C and D: the practical core of the Rules of the Road. The remaining parts of the Convention (general provisions, exemptions and the technical annexes) are not listed. Summaries are our own, based on the consolidated text of the International Regulations. This is not a legal text: when in doubt, the Convention decides.