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Rule 29: Pilot Vessels (COLREGS)

Last reviewed October 21, 2026

The short answer

Rule 29 says a vessel engaged on pilotage duty shows two all-round lights in a vertical line at or near the masthead, white over red. Underway she adds sidelights and a sternlight; at anchor she adds the Rule 30 anchor lights or shape. Off duty, she shows the lights of a similar vessel of her length.

The rule text

at or near the masthead, two all-round lights in a vertical line, the upper being white and the lower red;

International Rules, U.S. Coast Guard Navigation Rules and Regulations Handbook (NAVCEN, 2024 corrected edition), Rule 29

A pilot vessel when not engaged on pilotage duty shall exhibit the lights or shapes prescribed for a similar vessel of her length.

International Rules, U.S. Coast Guard Navigation Rules and Regulations Handbook (NAVCEN, 2024 corrected edition), Rule 29

What it means on the water

  • White over red at the masthead (29(a)(i)). Study trick: "white over red, pilot ahead."
  • Underway: add sidelights and sternlight (29(a)(ii)).
  • At anchor: add anchor light(s) or shape (29(a)(iii)).
  • Off duty: normal lights for her length (29(b)).
  • In fog, she may add an identity signal of four short blasts (Rule 35(k)).

International vs Inland

Same in substance. One wording difference: off duty, International 29(b) says the lights for a "similar vessel of her length"; Inland 29(b) says "a vessel of her length."

Common exam traps

  • Swapping white over red (pilot) with red over white (fishing).
  • Forgetting sidelights and sternlight when underway.

Try 3 questions on Rule 29

  1. White over red all-round lights mean:

    1. Fishing
    2. Pilot vessel on duty
    3. NUC
    4. Towing
    Show answer

    B. Pilot vessel on duty Rule 29(a)(i).

  2. A pilot vessel underway on duty adds:

    1. Masthead light only
    2. Sidelights and sternlight
    3. Towing light
    4. Nothing
    Show answer

    B. Sidelights and sternlight Rule 29(a)(ii).

  3. Pilot vessel identity signal in fog:

    1. Two prolonged
    2. Four short
    3. Three short
    4. One prolonged two short
    Show answer

    B. Four short Rule 35(k).

Frequently asked questions

What lights does a pilot boat show?

White over red all-round at or near the masthead, plus sidelights and sternlight underway (Rule 29).

What about off duty?

The lights for a similar vessel of her length (Rule 29(b)).

Same Inland?

Yes, in substance.

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