What light configuration indicates a tug and a long tow when the tug and tow exceeds 200 meters?

• A. White Over White
• B. Yellow Over White
• C. Three White Lights
• D. Red Over Red

Answer: (C)

Three white lights in a vertical line indicate a tug with a long tow. The top white light is the normal masthead light for a power-driven vessel, and the two lower white lights signal the towing arrangement when the tow length exceeds 200 meters. This pattern tells other mariners that a tug is actively towing a long tow and may have restricted maneuverability, so they should keep clear and proceed with caution. The other light patterns don’t signal a long tow in the same way, so they aren’t used to convey this situation.