Rules of the Road · Light Definitions & Visibility
Rule 20 states that lights required by the COLREGS shall be exhibited:
- AAt all times when underway
- BFrom sunset to sunrise only
- CFrom sunset to sunrise and during restricted visibility at all times✓ Correct
- DWhenever another vessel is within sight
Explanation
Rule 20(b) requires prescribed lights to be exhibited from sunset to sunrise and during restricted visibility — and may be exhibited at other times when the mariner considers it necessary. This ensures safety in both darkness and poor visibility.
Authority: 72 COLREGS Rule 20(b)
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