BOTH INTERNATIONAL & INLAND You are in charge of a power-driven vessel making way in dense fog. You observe what appears to be another vessel on radar half a mile distant on your port bow and closing. You must take which of the following actions?

Correct Answer: Option A — sound one prolonged blast

Rule 35(a) requires a power-driven vessel making way through the water in restricted visibility to sound at intervals of not more than 2 minutes one prolonged blast on its whistle, regardless of radar contacts.