In inland navigation, what lights must a single vessel being towed alongside show?

• A. A special flashing light, sidelights and a sternlight
• B. A white all-round light
• C. A red flare
• D. No lights are required

Answer: (A)

When a vessel is being towed alongside, it’s not under its own power, so other mariners must be able to identify its status and orientation clearly. The lights required reflect that: the standard navigation lights (sidelights to show its sides and a sternlight at the rear) plus a special flashing white light indicating that the vessel is being towed. This combination makes the tow’s status unmistakable at night and helps others judge how to pass or avoid the tow safely. A red flare is a distress signal, a white all-round light alone wouldn’t signal towing, and having no lights would be unsafe and noncompliant.