Green over white navigation lights indicate which activity?

• A. Trawling at night
• B. Fishing at night
• C. Not under command
• D. Towing at night

Answer: (A)

A green light above a white light shown in a vertical pair is a recognized signal that the vessel is trawling at night. This combination specifically indicates that gear is deployed and the vessel may have restricted maneuverability, so other vessels should exercise caution and avoid overlapping courses or crossing behind the vessel where the gear could pose a hazard. This pattern is distinct from other nighttime signals: towing at night uses a yellow towing light, not under command is indicated by red lights, and fishing at night without trawling isn’t signaled by this green-over-white pair.