Question 962 Rules of the Road

The correct answer is B) Two prolonged blasts at not more than two minute intervals. This is the correct answer because under both the International and Inland Navigation Rules, a power-driven vessel that is underway but stopped and making no way through the water must sound two prolonged blasts at intervals of not more than two minutes. This fog signal alerts other vessels in the vicinity that the vessel is underway but not moving. The other options are incorrect because option A calls for only one prolonged blast, option C calls for a one-minute interval between blasts which is too frequent, and option D calls for a two-minute interval between blasts which is the correct interval but the wrong number of blasts.