COLREGs · Rule 30
Anchored Vessels and Vessels Aground
Last verified: 2026-05-16
TL;DR
At anchor: forward all-round white (and a second all-round aft if 50 m+), or one ball by day. Aground: same as anchored plus two all-round red, or three balls by day.
Why it shows up on the exam
Vessels under 7 m at anchor not in or near a narrow channel may omit the anchor light or shape.
Authoritative source
Source links checked against the current public rule corpus on 2026-05-16.
- 33 CFR §83.30— verbatim Inland Rule text (US Code of Federal Regulations)(retrieved 2026-05-16)
- International COLREGs Rule 30 verbatim text is published by the IMO. The Inland counterpart 33 CFR §83 chunk above mirrors the international wording almost verbatim.
Inland parallel
Inland Rule 30 — Anchored Vessels and Vessels Aground →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 23 — Power-driven Vessel Underway
Drill COLREGs Rule 30
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