Towing & Ship-Assist · Lights — Towing Astern Length

A towing vessel shows three masthead lights in a vertical line (rather than two) when the length of the tow, measured from the stern of the tug to the after end of the tow, exceeds:

Explanation

Two masthead lights in a vertical line are shown for a tow of 200 m or less; three are shown when the tow exceeds 200 m. By day the tow also displays a diamond shape when over 200 m.

Authority: COLREGS/Navigation Rules, Rule 24(a)

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