145. BOTH INTERNATIONAL & INLAND A 20 meter vessel is towing another vessel astern. The length of the tow from the stern of the towing vessel to the stern of the tow is 75 meters. How many white towing masthead lights shall the towing vessel show at night?

A power-driven vessel towing another vessel astern must display two white masthead lights in a vertical line, as per Navigation Rules Rule 24(a). This requirement applies regardless of the tow length, unless it exceeds 200 meters, in which case three lights are required. The tow length of 75 meters is less than 200 meters, therefore two lights are required.