COLREG Rules
International Regulations for Preventing Collisions at Sea
A
Part A — General
3- 1 Application COLREG applies to all vessels on the high seas and in connected waters navigable by seagoing vessels, subject to closely conforming local special rules and IMO-adopted traffic separation schemes.
- 2 Responsibility Nothing in these Rules shall exonerate any vessel from the consequences of neglecting these Rules or neglecting any precaution required by ordinary practice of seamanship.
- 3 General Definitions Defines key terms used throughout the COLREGs including vessel, power-driven vessel, sailing vessel, restricted visibility, and more.
B
Part B — Steering & Sailing Rules
16Section I.Conduct in any condition of visibility
- 4 Application Rules in Section I apply in any condition of visibility.
- 5 Look-out Keep watch at all times with your eyes and ears, and use radar, AIS and every other means on board to judge the situation and the risk of collision.
- 6 Safe Speed Always go slowly enough that you can still avoid a collision and stop in time, judged against visibility, traffic, manoeuvrability and conditions.
- 7 Risk of Collision Every vessel shall use all available means to determine if risk of collision exists. If in doubt, such risk shall be deemed to exist.
- 8 Action to Avoid Collision When you act to avoid a collision, act early and make the change large enough for the other vessel to see, then check that it is working.
- 9 Narrow Channels In a narrow channel, stay on the starboard side as far as it is safe, and don't block vessels that can only navigate inside it.
- 10 Traffic Separation Schemes In a traffic separation scheme, follow your lane in the direction of the traffic, cross it at right angles if you must, and keep clear of the separation zone.
Section II.Conduct in sight of one another
- 11 Application Rules 11 to 18 cover vessels that can see each other with their own eyes, not only on radar.
- 12 Sailing Vessels When two sailing vessels approach, the one with wind on port side keeps clear. When both have wind on same side, the windward vessel keeps clear.
- 13 Overtaking If you are overtaking, it is your job to keep clear of the vessel ahead until you are past and well clear, whatever type of vessel you are.
- 14 Head-on Situation When two power-driven vessels in sight meet on reciprocal or nearly reciprocal courses with risk of collision, each shall alter to starboard to pass port to port.
- 15 Crossing Situation When two power-driven vessels are crossing, the vessel which has the other on her starboard side shall keep out of the way.
- 16 Action by Give-way Vessel As the give-way vessel, make your move early and make it big, so you pass at a safe distance and the other vessel can see what you are doing.
- 17 Action by Stand-on Vessel The stand-on vessel shall keep her course and speed, but may take action when it becomes apparent the give-way vessel is not acting.
- 18 Responsibilities Between Vessels Rule 18 sets the basic responsibilities between vessel types. Constrained-by-draught vessels receive special consideration but are not simply another rung in a fixed hierarchy.
C
Part C — Lights & Shapes
12- 20 Application (Lights) Show your navigation lights between sunset and sunrise and whenever visibility is poor, and day shapes during the day.
- 21 Definitions (Lights) Defines masthead light, sidelights, sternlight, towing light, all-round light and flashing light.
- 22 Visibility of Lights Specifies minimum visibility ranges for lights based on vessel length.
- 23 Power-driven Vessels Underway Power-driven vessels underway shall exhibit masthead light(s), sidelights, and sternlight. Vessels 50m+ require two masthead lights.
- 24 Towing and Pushing Vessels towing or pushing display additional masthead lights and a yellow towing light. Three masthead lights if tow exceeds 200m.
- 25 Sailing Vessels Underway and Vessels Under Oars Sailing vessels show sidelights and sternlight. May optionally show red over green all-round lights at the masthead.
- 26 Fishing Vessels Fishing vessels show green over white when trawling, red over white for other fishing, and sidelights plus sternlight when making way.
- 27 Vessels Not Under Command or Restricted in Ability to Manoeuvre NUC shows two red all-round lights vertically. RAM shows red-white-red all-round lights vertically.
- 28 Vessels Constrained by Their Draught A vessel limited by her draught can add three red all-round lights, one above the other, or a black cylinder by day.
- 29 Pilot Vessels A pilot vessel on duty shows white over red all-round lights at the masthead. When underway, also sidelights and sternlight.
- 30 Anchored Vessels and Vessels Aground Anchored vessels show an all-round white light forward and another aft (lower). Vessels aground additionally show two red all-round lights.
- 31 Seaplanes Where it is impracticable for a seaplane to exhibit lights of the exact characteristics, it shall exhibit lights as closely similar as possible.
D
Part D — Sound & Light Signals
6- 32 Definitions (Sound Signals) Whistle = any Annex III-compliant sound appliance. Short blast ≈ 1 s. Prolonged blast = 4-6 s. Get the duration wrong and the meaning changes.
- 33 Equipment for Sound Signals Whistle from 12 m, bell added from 20 m, gong added from 100 m — and the gong's tone must not be confused with the bell's.
- 34 Manoeuvring and Warning Signals One short blast means starboard, two means port, three means astern propulsion, and five or more rapid blasts mean doubt or danger.
- 35 Sound Signals in Restricted Visibility In restricted visibility, power-driven vessels making way sound one prolonged blast every 2 minutes. Vessels not making way sound two prolonged blasts.
- 36 Signals to Attract Attention To get another vessel's attention you can use a light or sound signal, as long as it can't be confused with any signal the rules define.
- 37 Distress Signals When in distress and requiring assistance, vessels shall use the signals described in Annex IV (red flares, SOS, MAYDAY, DSC, EPIRB and others).
E
Part E — Exemptions
1F
Part F — Verification of Compliance
3- 39 Definitions (Verification of Compliance) Defines the terms used by Part F: audit, Audit Scheme, Code for Implementation and audit standard — the vocabulary of the IMO Member State Audit Scheme.
- 40 Application (Verification of Compliance) Contracting Parties shall use the Code for Implementation when carrying out their obligations and responsibilities under the Convention.
- 41 Verification of Compliance Every Contracting Party is subject to periodic IMO audits verifying its compliance with and implementation of the Convention.
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