Question 916 Rules of the Road

The correct answer is C) Three short blasts. According to the International Regulations for Preventing Collisions at Sea (COLREGS) and the Inland Navigation Rules, a vessel operating with its propeller(s) turning astern is required to sound three short blasts on the whistle to indicate its maneuvering capabilities. This signal alerts other vessels in the area that the ship is operating in a manner that may be different from normal forward propulsion. The other options are incorrect because: A) One long blast is the signal for a vessel departing a dock or berth, B) One prolonged blast is the signal for a vessel warning of its presence in restricted visibility, and D) Four or more short blasts is the distress signal, not the signal for astern propulsion.