BOTH INTERNATIONAL & INLAND While underway in fog, you hear a prolonged blast from another vessel. Which vessel would sound this signal?

Correct Answer: Option C — A power-driven vessel making way

COLREGS Rule 35(a) mandates that a power-driven vessel making way through the water shall sound one prolonged blast at intervals of not more than two minutes. This signal provides audible notification of the vessel's presence and movement to others operating in restricted visibility conditions.