BOTH INTERNATIONAL & INLAND In a dense fog you hear a whistle signal ahead of one prolonged blast followed by three short blasts. Which vessel is required to sound this signal?

Correct Answer: Option A — A manned vessel being towed

Rule 35(c) dictates that a manned vessel being towed must sound one prolonged blast followed by three short blasts. This signal distinguishes the towed vessel from the towing vessel, which sounds one prolonged and two short blasts, ensuring clarity regarding the configuration of the tow in restricted visibility.