BOTH INTERNATIONAL & INLAND The white masthead light required for a power- driven vessel under the Rules is visible over how many degrees of the horizon?

Correct Answer: Option A — 225.0°

COLREGS Rule 21(a) mandates that a masthead light placed over the fore and aft centerline of a power-driven vessel must show an unbroken light over an arc of the horizon of 225.0 degrees, lighting from right ahead to 22.5 degrees abaft the beam on each side.