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Inland · Rule 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.

Source: 33 CFR §83.18Last verified 2026-05-16

Rule text#

Source

Verbatim 33 CFR §83.18 as published in the Code of Federal Regulations — public domain, retrieved 2026-05-16.

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. [USCG-2012-0102, 79 FR 37912, July 2, 2014, as amended by USCG-2012-0102, 79 FR 68621, Nov. 18, 2014]

(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. [USCG-2012-0102, 79 FR 37912, July 2, 2014, as amended by USCG-2012-0102, 79 FR 68621, Nov. 18, 2014]

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.

Authoritative source#

Source links checked against the current public rule corpus on 2026-05-16.

  • 33 CFR §83.18 — the section this text comes from, with its neighbours.
  • The Inland Navigation Rules are codified at 33 CFR Part 83 and are public domain. The international COLREGs text is published separately by the IMO.

Practice this rule#

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

A WIG craft is operating on the water surface on inland waters. Under Inland Rule 18, how is it treated for purposes of the responsibilities between vessels?

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Inland Rule 18: Responsibilities Between Vessels — USCG Captain's Exam Prep · CaptainsGround