COLREGs Rules 28-29: Draft-constrained vessels and pilot vessel lights

Last reviewed: October 14, 2026

Rule 28 lets an International vessel constrained by her draft show three red all-round lights or a cylinder; the Inland text is reserved. Rule 29 requires a vessel on pilotage duty to show a white-over-red masthead light pair, plus more lights when underway or at anchor.

Applies toRule 28 applies to International vessels constrained by their draft; Rule 29 applies to vessels engaged on pilotage duty and to pilot vessels not on pilotage duty.

What it says

  1. International: A vessel constrained by her draft may, in addition to the Rule 23 lights for power-driven vessels, show three all-round red lights in a vertical line, or a cylinder.

    “A vessel constrained by her draft may, in addition to the lights prescribed for power-driven vessels in Rule 23, exhibit where they can best be seen three all- round red lights in a vertical line, or a cylinder.”

  2. A vessel engaged on pilotage duty must show, at or near the masthead, two all-round lights in a vertical line, the upper white and the lower red.

    COLREGs Rules 28-29(a)(i)“at or near the masthead, two all-round lights in a vertical line, the upper being white and the lower red;”

  3. International: A vessel engaged on pilotage duty must, when underway, also show sidelights and a sternlight.

    COLREGs Rules 28-29(a)(ii)“when underway, in addition, sidelights and a sternlight;”

  4. International: A vessel engaged on pilotage duty that is at anchor must also show the anchor light, lights, or shape prescribed in Rule 30 for vessels at anchor, in addition to the lights in subparagraph (i).

    COLREGs Rules 28-29(a)(iii)“when at anchor, in addition to the lights prescribed in subparagraph (i), the anchor light, lights, or shape prescribed in Rule 30 for vessels at anchor.”

  5. Inland: A vessel engaged on pilotage duty that is at anchor must also show the anchor light, lights, or shape prescribed in Rule 30 (§ 83.30) for vessels at anchor.

    COLREGs Rules 28-29(a)(iii)“When at anchor, in addition to the lights prescribed in subparagraph (i) of this Rule, the anchor light, lights, or shape prescribed in Rule 30 (§ 83.30) for vessels at anchor.”

  6. International: A pilot vessel not engaged on pilotage duty must show the lights or shapes prescribed for a similar vessel of her length.

    COLREGs Rules 28-29(b)“A pilot vessel when not engaged on pilotage duty shall exhibit the lights or shapes prescribed for a similar vessel of her length.”

  7. Inland: A pilot vessel not engaged on pilotage duty must show the lights or shapes prescribed for a vessel of her length.

    COLREGs Rules 28-29(b)“A pilot vessel when not engaged on pilotage duty shall exhibit the lights or shapes prescribed for a vessel of her length.”

Common questions

What lights may a vessel constrained by her draft show?

International: she may show three all-round red lights in a vertical line, or a cylinder, in addition to the Rule 23 lights. The Inland text is reserved.

“exhibit where they can best be seen three all- round red lights in a vertical line, or a cylinder.”

What lights does a pilot vessel on pilotage duty show?

It must show two all-round lights in a vertical line at or near the masthead, the upper white and the lower red. When underway it also shows sidelights and a sternlight.

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

What lights does a pilot vessel show when not on pilotage duty?

It must show the lights or shapes prescribed for a vessel of her length. The International text says a similar vessel of her length.

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

The text of COLREGs Rules 28-29

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

Rule 28: Vessels Constrained by Their Draft; Rule 29: Pilot Vessels

International (COLREGs)

A vessel constrained by her draft may, in addition to the lights prescribed for power-driven vessels in Rule 23, exhibit where they can best be seen three all- round red lights in a vertical line, or a cylinder. Vessel constrained by her draft—underway – 50 meters or greater in length.

Inland Rules

[Reserved]

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International (COLREGs)

(a) A vessel engaged on pilotage duty shall exhibit: (i) at or near the masthead, two all-round lights in a vertical line, the upper being white and the lower red; (ii) when underway, in addition, sidelights and a sternlight; (iii) when at anchor, in addition to the lights prescribed in subparagraph (i), the anchor light, lights, or shape prescribed in Rule 30 for vessels at anchor. (b) A pilot vessel when not engaged on pilotage duty shall exhibit the lights or shapes prescribed for a similar vessel of her length. Vessel engaged on pilotage duty—underway. Same for Inland.

Inland Rules

Pilot vessels (a) A vessel engaged on pilotage duty shall exhibit: (i) At or near the masthead, two all-round lights in a vertical line, the upper being white and the lower red; (ii) When underway, in addition, sidelights and a sternlight; and (iii) When at anchor, in addition to the lights prescribed in subparagraph (i) of this Rule, the anchor light, lights, or shape prescribed in Rule 30 (§ 83.30) for vessels at anchor. (b) A pilot vessel when not engaged on pilotage duty shall exhibit the lights or shapes prescribed for a vessel of her length. Vessel engaged on pilotage duty—at anchor; vessel of less than 50 meters in length. Same for International.

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.