The Steering and Sailing Rules: who gives way

Part B of the COLREG is Rules 4-19: how to keep a look-out, what speed is safe, and who keeps out of whose way when courses meet. Each rule here comes with its full text and a short practice commentary written from the bridge, not from the textbook.

The shortest crib

Between vessels in sight of one another, the duties are ordered by the Rule 18 ladder: vessel not under command → vessel restricted in her ability to manoeuvre → vessel engaged in fishing → sailing vessel → power-driven vessel (each rung keeps out of the way of the rungs above it; the vessel engaged in fishing owes that duty only so far as possible, Rule 18 sets no duty at all between a vessel not under command and one restricted in her ability to manoeuvre, and Rules 9, 10 and 13 beat the ladder). The overtaking vessel gives way always (Rule 13). Head-on: both alter to starboard (Rule 14). Crossing: the one with the other on her starboard side gives way (Rule 15). Once vessels are no longer in sight of one another, in or near an area of restricted visibility, Rule 19 takes over: nobody is the give-way vessel and each one judges the risk for herself.

The whole logic on one page: who has the right of way at sea.

Section I: Conduct of vessels in any condition of visibility

Rule 4 Application Rules in this Section apply to any condition of visibility.

Rule 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. Rule 6 Safe Speed There is no single safe number of knots: safe speed is always a function of the conditions. Rule 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. Rule 8 Action to Avoid Collision The manoeuvre is to be bold, made early and readable for the other vessel, both visually and on radar. Rule 9 Narrow Channels Keep as near to the starboard outer limit of the channel or fairway as is safe and practicable. Rule 10 Traffic Separation Schemes A TSS is a motorway at sea: you follow your lane, in the general direction of traffic flow.

Section II: Conduct of vessels in sight of one another

Rule 11 Application Rules in this section apply to vessels in sight of one another.

Rule 12 Sailing Vessels Different tacks: the vessel with the wind on the port side gives way. Rule 13 Overtaking Overtaking means giving way. Always, whatever the type of vessel (it beats the Rule 18 ladder). Rule 14 Head-on Situation Head-on: BOTH vessels alter course to starboard and pass port to port. Rule 15 Crossing Situation She is on your starboard side: you give way. You are on hers: she gives way. Rule 16 Action by Give-way Vessel You are giving way: do it early and boldly, so the other bridge has no doubts. Rule 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. Rule 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.

Section III: Conduct of vessels in restricted visibility

Rule 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.

Practise: the situations trainer Right of way: the one-page crib Index of all the Rules Lights and shapes (trainer)

Rule text per the consolidated U.S. Coast Guard print of the International Regulations (public domain); spelling follows the IMO original. The practice notes are our own. This is not a legal text: when in doubt, the Convention decides. Inland waters have their own, different rules.