Lead: Except where Rules 9, 10 and 13 require
Except where Rules 9, 10 and 13 otherwise require, the following order of responsibilities applies:
COLREGs trainerPart B: Steering and Sailing Rules
Rule 18
Responsibilities Between Vessels
Power-driven keeps clear of NUC, RAM, fishing and sailing; sailing of NUC, RAM and fishing; fishing of NUC and RAM. All but NUC and RAM avoid impeding a CBD.
Wording follows the International Regulations as printed in the US Coast Guard Navigation Rules handbook (2024), with British spelling, and is shortened in places. Download the rules
Read the whole of Rule 18 on one page
Lead: Except where Rules 9, 10 and 13 require
Except where Rules 9, 10 and 13 otherwise require, the following order of responsibilities applies:
Paragraph (a): A power-driven vessel keeps clear of
(i) a vessel not under command; (ii) a vessel restricted in her ability to manoeuvre; (iii) a vessel engaged in fishing; (iv) a sailing vessel.
Paragraph (b): A sailing vessel keeps clear of
(i) a vessel not under command; (ii) a vessel restricted in her ability to manoeuvre; (iii) a vessel engaged in fishing.
Paragraph (c): A fishing vessel underway keeps clear of
So far as possible: (i) a vessel not under command; (ii) a vessel restricted in her ability to manoeuvre.
Paragraph (d): Constrained by draught
(i) Any vessel other than one not under command or restricted in her ability to manoeuvre shall, if circumstances admit, avoid impeding the safe passage of a vessel constrained by her draught, exhibiting the Rule 28 signals. (ii) A vessel constrained by her draught shall navigate with particular caution, with full regard to her special condition.
Paragraph (e): Seaplanes
A seaplane on the water shall in general keep well clear of all vessels and avoid impeding their navigation; but where risk of collision exists she shall comply with the Rules of this Part.
Paragraph (f): WIG craft
(i) A WIG craft shall, when taking off, landing and in flight near the surface, keep well clear of all other vessels and avoid impeding their navigation; (ii) A WIG craft operating on the water surface shall comply with the Rules of this Part as a power-driven vessel.
Test yourself on Rule 18
- A power-driven vessel underway must keep out of the way of all of the following EXCEPT one. Which?
- Another power-driven vessel of equal status. Rule 18: a power-driven vessel keeps clear of NUC, RAM, fishing and sailing vessels. Two power-driven vessels of equal status follow the crossing/head-on/overtaking rules instead.
A training aid, not the official text. The COLREGs are an IMO convention, and your national authority publishes the version that applies in its waters. Check the rules themselves before you rely on them at sea. Download the rules.