A vessel being towed astern must display which light arrangement?

• A. Masthead lights
• B. Sidelights
• C. Stern light
• D. All-around red light

Answer: (B)

When a vessel is being towed astern, its position and heading are most clearly indicated to other traffic by lights on the sides. The sidelights (port and starboard) are visible to approaching vessels from the sides and help others judge the towed vessel’s course and potential risk of collision. Masthead or stern lights are associated with a vessel underway on its own power, and can be misleading or unnecessary for the towed vessel since its propulsion isn’t in use. An all-around red light is used in different, specific situations that aren’t relevant to a normal towing arrangement. So the towed vessel should display sidelights to ensure proper visibility and safe navigation.