Question 399 Rules of the Road

The correct answer is D) When overtaking in a narrow channel. According to the International Regulations for Preventing Collisions at Sea (COLREGS), a vessel overtaking another vessel in a narrow channel must sound the whistle signal of two prolonged blasts followed by one short blast to indicate its intention to overtake. This signal is used to alert the vessel being overtaken and any other vessels in the vicinity that an overtaking maneuver is about to occur in the confined waters of a narrow channel. The other options are incorrect because the two-prolonged-one-short whistle signal is specifically required for overtaking in a narrow channel, not in open waters (A), in restricted visibility (B), or when no other vessels are present (C).