Rule 23 · USCG Navigation Rules

Power-driven vessel under 7 m (max speed 7 knots)

under 7 mInternational only

A vessel under 7 m whose maximum speed does not exceed 7 knots may show only an all-round white light — sidelights if practicable.

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 light

→ Power-driven vessel under 7 m (max speed 7 knots) — Underway, seen from the port bow.

International Rules onlyapplies to your current setting

The Inland Rules have NO 7 m / 7 knot provision. On US inland waters the smallest applicable option is the under-12 m rule: an all-round white light plus sidelights.

Choose International or Inland in language and regional settings in the site header.

Memory aid

“Under 7 m AND under 7 knots: one white light is enough (International only).”

What it means

Underway

Shall, if practicable, also exhibit sidelights. Only lawful when maximum speed does not exceed 7 knots.

Day shapes

No special day shape — by day this vessel is recognised by sight, not by shapes.

Light details

Light	Colour	Arc	Position
All-round white light	white	360° all-round	Forward masthead position

2D profile

Labelled side view — works without WebGL and in print. Variant shown: Underway.

Side view, seen from starboard — only the lights visible from that side are shown.

From dead ahead (her green appears on your left).

From astern.

In fog, she sounds

Power-driven vessel making way (fog)—

One prolonged blast at intervals of not more than 2 minutes — a power-driven vessel making way through the water in restricted visibility.

Don’t confuse with…

Power-driven vessel under 12 m

Rule 23

Vessel at anchor (under 50 m)

Rule 30

Official source

Rule 23, reproduced from the public-domain COLREGs Rule 23(d)(ii) — USCG Navigation Rules. Diagrams and 3D scenes are original to boatrules.com.

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