BOTH INTERNATIONAL & INLAND A vessel is towing and carrying the required lights on the masthead. What is the visibility arc of these lights?

Correct Answer: Option C — 225.0°

Rule 21(a) defines the masthead light as a white light placed over the fore and aft centerline of the vessel, showing an unbroken light over an arc of 225 degrees. This arc is fixed from dead ahead to 22.5 degrees abaft the beam on either side of the vessel.