COLREGs Annex V: Pilot Rules and interpretative rules

Last reviewed: October 14, 2026

This section has Coast Guard interpretative rules for the 72 COLREGS and the Inland Rules, plus inland Pilot Rules. The interpretative rules explain composite units, vessels at anchor and unmanned towed barges. The inland Pilot Rules allow special flashing lights for law enforcement and public safety vessels.

Applies toInland: the Pilot Rules part applies to all vessels operating on United States inland waters and to United States vessels operating on the Canadian waters of the Great Lakes to the extent there is no conflict with Canadian law.

What it says

  1. International: A composite unit is a pushing vessel rigidly connected by mechanical means to a vessel being pushed, so they react to sea and swell as one vessel.

    “A “composite unit” is interpreted to be a pushing vessel that is rigidly connected by mechanical means to a vessel being pushed so they react to sea and swell as one vessel.”

  2. International: Mechanical means does not include lines, hawsers, wires or chains.

    ““Mechanical means” does not include the following:”

  3. International: For Rule 30, a barge made fast to one or more mooring buoys or similar devices attached to the sea or river floor counts as a vessel at anchor.

    “a vessel at anchor includes a barge made fast to one or more mooring buoys or other similar device attached to the sea or river floor.”

  4. Inland: Law enforcement vessels may display a flashing blue light when engaged in direct law enforcement or public safety activities, and the light must not interfere with the visibility of the vessel's navigation lights.

    COLREGs Annex V(a)“Law enforcement vessels may display a flashing blue light when engaged in direct law enforcement or public safety activities.”

  5. Inland: Vessels using the red and yellow identification light signal during public safety activities must abide by the Inland Navigation Rules and must not presume the light or the exigency gives them precedence or right of way.

    COLREGs Annex V(a)“must abide by the Inland Navigation Rules, and must not presume that the light or the exigency gives them precedence or right of way.”

  6. An unmanned barge being towed may use the exception of COLREGS Rule 24(h), but the exception applies only to the vertical sector requirements.

    “However, this exception only applies to the vertical sector requirements.”

Common questions

What is a composite unit under the Inland interpretative rules?

Inland: it is a pushing vessel and a vessel being pushed ahead that are rigidly connected by mechanical means so they react to sea and swell as one vessel. Mechanical means does not include lines, wires, hawsers, or chains.

“A “composite unit” is interpreted to be the combination of a pushing vessel and a vessel being pushed ahead that are rigidly connected by mechanical means so they react to sea and swell as one vessel.”

Who may display a flashing blue light?

Inland: law enforcement vessels of the United States and the States and their political subdivisions may display it.

“may be displayed by law enforcement vessels of the United States and the States and their political subdivisions.”

Does the red and yellow flashing light give right of way?

Inland: no. The light conveys no special privilege and may be used only as an identification signal.

“The identification light signal may be used only as an identification signal and conveys no special privilege.”

The text of COLREGs Annex V

U.S. Coast Guard, Navigation Rules and Regulations Handbook

Pilot Rules

International (COLREGs)

INTERPRETATIVE RULES This part contains the interpretative rules concerning the 72 COLREGS that are adopted by the Coast Guard for the guidance of the public. Rule 24(b) of the 72 COLREGS states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power-driven vessel and must exhibit the lights under Rule 23. A “composite unit” is interpreted to be a pushing vessel that is rigidly connected by mechanical means to a vessel being pushed so they react to sea and swell as one vessel. “Mechanical means” does not include the following:

(a) Lines.

(b) Hawsers.

(c) Wires.

(d) Chains. For the purposes of Rule 30 of the 72 COLREGS, a vessel at anchor includes a barge made fast to one or more mooring buoys or other similar device attached to the sea or river floor. Such a barge may be lighted as a vessel at anchor in accordance with Rule 30, or may be lighted on the corners in accordance with 33 CFR 83.30(h) through (l). An unmanned barge being towed may use the exception of COLREGS Rule 24(h). However, this exception only applies to the vertical sector requirements.

Inland Rules

Pilot Rules This Part applies to all vessels operating on United States inland waters and to United States vessels operating on the Canadian waters of the Great Lakes to the extent there is no conflict with Canadian law. The terms used in this part have the same meaning as the terms defined in Part 83 of this subchapter.

(a) Law enforcement vessels may display a flashing blue light when engaged in direct law enforcement or public safety activities. This light must be located so that it does not interfere with the visibility of the vessel’s navigation lights.

(b) The blue light described in this section may be displayed by law enforcement vessels of the United States and the States and their political subdivisions.

(a) Vessels engaged in government sanctioned public safety activities, and commercial vessels performing similar functions, may display an alternately flashing red and yellow light signal. This identification light signal must be located so that it does not interfere with the visibility of the vessel’s navigation lights. The identification light signal may be used only as an identification signal and conveys no special privilege. Vessels using the identification light signal during public safety activities must abide by the Inland Navigation Rules, and must not presume that the light or the exigency gives them precedence or right of way.

(b) Public safety activities include but are not limited to patrolling marine parades, regattas, or special water celebrations; traffic control; salvage; firefighting; medical assistance; assisting disabled vessels; and search and rescue. INTERPRETATIVE RULES This part contains the interpretative rules for the Inland Rules. These interpretative rules are intended as a guide to assist the public and promote compliance with the Inland Rules. Rule 24(b) of the Inland Rules states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power-driven vessel and must exhibit the lights prescribed in Rule 23. A “composite unit” is interpreted to be the combination of a pushing vessel and a vessel being pushed ahead that are rigidly connected by mechanical means so they react to sea and swell as one vessel. Mechanical means does not include lines, wires, hawsers, or chains. A vessel at anchor includes a vessel made fast to one or more mooring buoys or other similar device attached to the ocean floor. Such vessels may be lighted as a vessel at anchor in accordance with Rule 30, or may be lighted on the corners in accordance with 33 CFR 83.30(h) through (l). An unmanned barge being towed may use the exception of COLREGS Rule 24(h). However, this exception only applies to the vertical sector requirements.

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 August 12, 2024. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.