33 CFR 83.18: Responsibilities between vessels under Rule 18

Last reviewed: October 26, 2026

Rule 18 says which vessels must keep out of the way of other vessels. It sets the order for power-driven vessels, sailing vessels and vessels engaged in fishing, and covers seaplanes and WIG craft. It applies except where Rules 9, 10, and 13 (§§ 83.09, 83.10, and 83.13) otherwise require.

Applies toPower-driven vessels underway, sailing vessels underway, vessels engaged in fishing, seaplanes on the water, and WIG craft.

What it says

  1. A power-driven vessel underway must keep 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.

    33 CFR 83.18(a)“A power-driven vessel underway shall keep out of the way of:”

  2. A sailing vessel underway must 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.

    33 CFR 83.18(b)“A sailing vessel underway shall keep out of the way of:”

  3. A vessel engaged in fishing when underway must, so far as possible, keep out of the way of a vessel not under command and a vessel restricted in her ability to maneuver.

    33 CFR 83.18(c)“A vessel engaged in fishing when underway shall, so far as possible, keep out of the way of:”

  4. A seaplane on the water must, in general, keep well clear of all vessels and avoid impeding their navigation.

    33 CFR 83.18(e)“A seaplane on the water shall, in general, keep well clear of all vessels and avoid impeding their navigation.”

  5. Where risk of collision exists, a seaplane must comply with the Rules of this Subpart (Rules 4-19) (§§ 83.04 through 83.19).

    33 CFR 83.18(e)“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”

  6. A WIG craft must keep well clear of all other vessels and avoid impeding their navigation when taking off, landing and in flight near the surface.

    33 CFR 83.18(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”

  7. A WIG craft operating on the water surface must comply with the Rules of this Subpart (Rules 4-19) (§§ 83.04 through 83.19) as a power-driven vessel.

    33 CFR 83.18(f)(ii)“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.”

Common questions

Does a power-driven vessel have to keep out of the way of a sailing vessel?

Yes. A power-driven vessel underway must keep out of the way of a sailing vessel, except where Rules 9, 10, and 13 otherwise require.

“A power-driven vessel underway shall keep out of the way of:”

Who must a sailing vessel keep out of the way of?

A sailing vessel underway must 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 sailing vessel underway shall keep out of the way of:”

How must a WIG craft behave on the water surface?

A WIG craft operating on the water surface must comply with the Rules of this Subpart (Rules 4-19) as a power-driven vessel.

“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.”

What must a seaplane on the water do about other vessels?

A seaplane on the water must, in general, keep well clear of all vessels and avoid impeding their navigation.

“A seaplane on the water shall, in general, keep well clear of all vessels and avoid impeding their navigation.”

The text of 33 CFR 83.18

Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR

Responsibilities between vessels (Rule 18)

Except where Rules 9, 10, and 13 (§§ 83.09, 83.10, and 83.13) otherwise require:

(a) A power-driven vessel underway shall keep out of the way of:

(i) A vessel not under command;

(ii) A vessel restricted in her ability to maneuver;

(iii) A vessel engaged in fishing;

(iv) A sailing vessel.

(b) A sailing vessel underway shall keep out of the way of:

(i) A vessel not under command;

(ii) A vessel restricted in her ability to maneuver; and

(iii) A vessel engaged in fishing.

(c) A vessel engaged in fishing when underway shall, so far as possible, keep out of the way of:

(i) A vessel not under command; and

(ii) A vessel restricted in her ability to maneuver.

(d) [Reserved]

(e) 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

(ii) 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.

Sections it refers to

The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of April 16, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.