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COLREGs · Rule 18 · 33 CFR §83.18

Responsibilities Between Vessels

The pecking order: NUC > RAM > CBD (international only) > fishing > sailing > power-driven. Each must keep out of the way of the categories above. Seaplanes and WIG craft are special cases.

What does Rule 18 actually say?#

Source

Verbatim 33 CFR §83.18, public domain. The international COLREGs text is published by the IMO and cannot be reproduced here; this U.S. wording tracks it closely.
Except where Rules 9, 10, and 13 (§§ 83.09, 83.10, and 83.13) otherwise require:
A power-driven vessel underway shall keep out of the way of:
A vessel not under command;
A vessel restricted in her ability to maneuver;
A vessel engaged in fishing;
A sailing vessel.
A sailing vessel underway shall keep out of the way of:
A vessel not under command;
A vessel restricted in her ability to maneuver; and
A vessel engaged in fishing.
A vessel engaged in fishing when underway shall, so far as possible, keep out of the way of:
A vessel not under command; and
A vessel restricted in her ability to maneuver.
[Reserved]
A seaplane on the water shall, in general, keep well clear of all vessels and avoid impeding their navigation. In circumstances, however, where risk of collision exists, she shall comply with the Rules of this Subpart (Rules 4-19) (§§ 83.04 through 83.19); and (f)(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; and
a WIG craft operating on the water surface shall comply with the Rules of this Subpart (Rules 4-19) (§§ 83.04 through 83.19) as a power-driven vessel. [USCG-2012-0102, 79 FR 37912, July 2, 2014, as amended by USCG-2012-0102, 79 FR 68621, Nov. 18, 2014]
A power-driven vessel underway shall keep out of the way of:
A vessel not under command;
A vessel restricted in her ability to maneuver;
A vessel engaged in fishing;
A sailing vessel.
A sailing vessel underway shall keep out of the way of:
A vessel not under command;
A vessel restricted in her ability to maneuver; and
A vessel engaged in fishing.
A vessel engaged in fishing when underway shall, so far as possible, keep out of the way of:
A vessel not under command; and
A vessel restricted in her ability to maneuver.
[Reserved]
A seaplane on the water shall, in general, keep well clear of all vessels and avoid impeding their navigation. In circumstances, however, where risk of collision exists, she shall comply with the Rules of this Subpart (Rules 4-19) (§§ 83.04 through 83.19); and (f)(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; and
a WIG craft operating on the water surface shall comply with the Rules of this Subpart (Rules 4-19) (§§ 83.04 through 83.19) as a power-driven vessel. [USCG-2012-0102, 79 FR 37912, July 2, 2014, as amended by USCG-2012-0102, 79 FR 68621, Nov. 18, 2014]

Practice this rule#

One real exam question on this rule, cited to source. No sign-up.

Rule 18 — Responsibilities Between Vessels

Rules 11 through 18 of the Inland Navigation Rules apply under which specific condition?

How does Inland Rule 18 differ from COLREGs?#

Inland Rule 18 reserves paragraph (d). Under COLREGs, 18(d) is the paragraph about vessels constrained by their draught — and since there is no Inland Rule 28 and no Inland 'constrained by draft' status, the Inland text has nothing to put there. The pecking order in paragraphs (a) through (c) is otherwise the same in both rule sets.

21 of 38 rules differ somewhere; the five the exam leans on are Rule 9, Rule 10, Rule 24, Rule 28 and Rule 34, side by side on Inland vs International Rules.

Why it shows up on the exam#

Memorise the order: 'New Reels Catch Fish So Powerfully'. Rule 18 is the most-asked rule in the entire module.

What does the exam actually test here?#

  1. The order

    NUC, RAM, fishing, sail, power

    A power-driven vessel keeps out of the way of a vessel not under command, a vessel restricted in her ability to maneuver, a vessel engaged in fishing, and a sailing vessel. A sailing vessel keeps clear of the first three. A fishing vessel keeps clear, so far as possible, of the first two.

  2. The three overrides

    Rules 9, 10 and 13

    Rule 18 opens 'except where Rules 9, 10, and 13 otherwise require'. In a narrow channel, in a traffic separation scheme, or when overtaking, the pecking order does not save you — which is why 'the sailing vessel always has right of way' is a wrong answer.

  3. Seaplanes and WIG

    Keep well clear

    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 complies with Rules 4–19. A WIG craft keeps well clear when taking off, landing, and in flight near the surface, and complies as a power-driven vessel when on the surface.

Rule 18 — common exam questions#

What is the order of responsibility in Rule 18?

A power-driven vessel gives way to a vessel not under command, a vessel restricted in her ability to maneuver, a vessel engaged in fishing, and a sailing vessel. A sailing vessel gives way to the first three; a fishing vessel gives way, so far as possible, to the first two (33 CFR §83.18).

Does a sailing vessel always have right of way over a power-driven vessel?

No. Rule 18 is expressly subject to Rules 9, 10, and 13, so a sailing vessel must not impede a vessel confined to a narrow channel or a lane in a traffic separation scheme, and must keep clear when she is overtaking.

Where does a fishing vessel sit in the order?

Below a vessel not under command and a vessel restricted in her ability to maneuver — it must keep out of their way so far as possible — and above sailing and power-driven vessels, which must keep out of its way (33 CFR §83.18(a), (b), (c)).

Does Rule 18 apply in fog?

Not to vessels that cannot see each other. Rule 18 sits in the section governing vessels in sight of one another; an encounter in restricted visibility where the vessels are not in sight is governed by Rule 19, which has no pecking order at all.

Authoritative source#

  • 33 CFR §83.18 — this section with its neighbours. 33 CFR Part 83 is public domain; checked 2026-05-16.
  • COLREGs Rule 18 is published by the IMO and is authoritative internationally.

Practise this rule against the real exam.

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