Navigation lights — quick reference

COLREG 1972, Rules 20–31. Diagrams are schematic representations of how the lights stack as seen from astern looking forward — they are a memory aid, not the regulatory positions.

• Power-driven vessel underway (≥ 50 m)

  Rule 23(a)

  Two masthead lights (white) with the second higher and abaft, plus sidelights (green stbd, red port) and sternlight (white).

• Power-driven vessel underway (< 50 m)

  Rule 23(a)(i)

  Single masthead, sidelights, sternlight.

• Sailing vessel underway

  Rule 25

  Sidelights + sternlight. Optional red-over-green at the masthead.

  Optional red-over-green at masthead.

• Vessel at anchor (< 50 m)

  Rule 30(a)

  One all-round white light, exhibited where best seen.

  All-round white forward.

• Vessel at anchor (≥ 50 m)

  Rule 30(a)

  All-round white forward + a second all-round white aft, lower.

  All-round white forward, second lower aft.

• Vessel aground

  Rule 30(d)

  At-anchor lights plus two all-round red in vertical line.

  At-anchor lights + two red all-round in vertical line.

• Towing (length of tow ≤ 200 m)

  Rule 24(a)

  Two masthead in vertical line, sidelights, sternlight, plus a yellow towing light above the sternlight.

  Yellow towing light above the sternlight.

• Towing (length of tow > 200 m)

  Rule 24(a)

  Three masthead in vertical line, otherwise as for short tow.

• Fishing (not trawling)

  Rule 26(c)

  Red over white all-round in a vertical line. Sidelights + sternlight only when making way.

  Sidelights + sternlight only when making way.

• Trawling

  Rule 26(b)

  Green over white all-round in a vertical line. Sidelights + sternlight only when making way.

• Not under command

  Rule 27(a)

  Two all-round red in vertical line. Sidelights + sternlight only when making way through the water.

  Sidelights + sternlight only when making way.

• Restricted in ability to manoeuvre

  Rule 27(b)

  Red-white-red all-round in vertical line. Plus the lights for a power-driven vessel when making way.

• Constrained by draught

  Rule 28

  Three all-round red in a vertical line, in addition to lights for a power-driven vessel.

  Three red all-round in addition to power-driven lights.

• Pilot vessel underway

  Rule 29

  White over red all-round in vertical line, plus sidelights and sternlight when underway.