Question 605 Rules of the Road

You are correct, the answer is A) Sound one prolonged blast. According to the International Regulations for Preventing Collisions at Sea (COLREGS) and the Inland Navigation Rules, when operating in dense fog, a power-driven vessel making way must sound one prolonged blast at intervals not exceeding 2 minutes. This alerts other vessels in the area to your presence and intended movement, allowing them to take appropriate action to avoid a collision. The other options are incorrect because they do not match the required action for a power-driven vessel operating in dense fog. Exchanging passing signals (B), sounding one short, one prolonged, and one short blast (C), or sounding the danger signal (D) are not the appropriate responses in this situation.