Rule 30 · USCG Navigation Rules
Vessel at anchor (under 50 m)
One all-round white light where it can best be seen — and one ball forward by day.
Viewpoint
Display
Drag to orbit freely, scroll or pinch to zoom — or use the viewpoint buttons above (keyboard friendly).
From the port bow you see:
- All-round white anchor light
→ Vessel at anchor (under 50 m) — At anchor, seen from the port bow.
US Inland difference
Inland Rule 30: a vessel under 20 m at anchor in a designated special anchorage area is not required to show anchor lights or shapes.
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Memory aid
“Asleep on the hook: one white ball of light by night, one black ball by day.”
What it means
At anchor
Under 50 m a single all-round white where best seen suffices. A vessel under 7 m anchored clear of channels, fairways and anchorages needs no light or ball at all.
Day shapes
Anchor ball
One ball in the fore part where it can best be seen.
Light details
| Light | Colour | Arc | Position |
|---|---|---|---|
| All-round white anchor light | white | 360° all-round | Forward, centreline |
2D profile
Labelled side view — works without WebGL and in print. Variant shown: At anchor.
In fog, she sounds
Don’t confuse with…
Official source
Rule 30, reproduced from the public-domain COLREGs Rule 30 — USCG Navigation Rules. Diagrams and 3D scenes are original to boatrules.com.