Inland · Rule 23
Power-driven Vessel Underway
Last verified: 2026-05-16
TL;DR
A masthead light forward, a second masthead light abaft and higher (if 50 m+), sidelights, and a sternlight. Vessels under 12 m may show an all-round white in lieu of masthead+stern.
Authoritative source
Source links checked against the current public rule corpus on 2026-05-16.
International parallel
COLREGs Rule 23 — Power-driven Vessel Underway →More from Part C — Lights and Shapes
Related drills
- Rule 20 — Application (Lights and Shapes)
- Rule 21 — Definitions (Lights)
- Rule 22 — Visibility of Lights
- Practise Rule 24 — Towing and Pushing
Drill Inland Rule 23
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