Question 507 Rules of the Road

The correct answer is B) 2 masthead lights. According to the International Regulations for Preventing Collisions at Sea (COLREGS), a towing vessel 35 meters in length, with a tow 100 meters astern, must show a minimum of two masthead lights. This is because the towing vessel is considered an "Inconspicuous, partly submerged vessel or object being towed" and must display the lights prescribed for such vessels in Rule 24(c) of the COLREGS. The other options are incorrect because a single masthead light (option A) is not sufficient, and three or four masthead lights (options C and D) would be for larger vessels or formations, not a single towing vessel with a 100-meter tow.