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COLREG

Rule 29: Pilot Vessels

COLREG: white over red, pilot ahead; underway or at anchor add lights or shapes; off duty uses those for a similar vessel of her length.

Rule 29 of 41

Decide

An interactive 3D illustration is shown here. The same content is described in the rule text and key takeaways below.

Decision 1 of 2

It is night and you see only these lights. What vessel is it?

The rule in plain words

  1. Which lights identify pilotage duty?At or near the masthead, she shows two all-round lights in a vertical line; the upper is white and the lower is red.
  2. What is added when underway?Besides the masthead pair, she shows sidelights and a sternlight.
  3. What changes when she is at anchor?In addition to the lights in (i), she shows the anchor light, lights, or shape prescribed in Rule 30.
  4. What if she is not on pilotage duty?She shows the lights or shapes prescribed for a similar vessel of her length.
Identification detail. A vessel on pilotage duty shows white over red all-round lights. When underway, it also shows sidelights and a sternlight. At anchor, it adds the applicable anchor light(s). The applicable anchor day shape is also required.

Before you read on: what would you do?

Question 1/1

A vessel engaged on pilotage duty: what does she show at the masthead?

See it in 3D

Drag the vessel to turn it: this is how her lights look at night.

An interactive 3D illustration is shown here. The same content is described in the rule text and key takeaways below.

Frequent mistakes

  • Wrong: "White over red means she is at anchor."

    Right: It marks pilotage duty; at anchor she also shows the Rule 30 light, lights, or shape.

  • Wrong: "When underway she shows only the masthead pair."

    Right: When underway, she adds sidelights and a sternlight.

  • Wrong: "Off duty she always keeps the pilotage lights."

    Right: Off duty, she shows the lights or shapes for a similar vessel of her length.

Exam keys & interpretation

  1. "Engaged on pilotage duty" activates white over red; "not engaged" points to a similar vessel.
  2. "When underway" means sidelights and a sternlight in addition to the vertical pair.
  3. "At anchor" does not remove the vertical pair: add the Rule 30 light, lights, or shape.

How to read it

Classify the status first: pilotage duty, underway, or at anchor; then add the required lights or shapes.

When not engaged on pilotage duty, apply the lights or shapes prescribed for a similar vessel of her length.

Key points

  • Pilotage duty → white above red · vertical pair.
  • Underway → add sidelights + sternlight.
  • At anchor → add Rule 30: light, lights, or shape.
  • Off duty → lights or shapes for a similar vessel of her length.

Test your knowledge

3 questions to check it. Pick an answer to see why.

Question 1/3

When underway, what does a vessel engaged on pilotage duty add?

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Official text

IMO COLREG 1972 U.S. Coast Guard — International Navigation Rules (2024)

Full wording of the rule, reproduced from the official source below.

(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.
Source:

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Reviewed by Ramon Curto, Nautical teacher at IECNPC · Last reviewed:

Frequently asked questions about COLREG Rule 29

What lights does a pilot vessel on pilotage duty show?

Two all-round lights in a vertical line at or near the masthead, the upper white and the lower red (Rule 29(a)). When underway she adds sidelights and a sternlight, and when at anchor she shows the anchor lights prescribed in Rule 30.

What does white over red at the masthead mean?

A vessel engaged on pilotage duty. Rule 29(a) prescribes two all-round lights in a vertical line, the upper white and the lower red, at or near the masthead.

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

The lights or shapes prescribed for a similar vessel of her length (Rule 29(b)). The white-over-red signal belongs only to a vessel actually engaged on pilotage duty.