What does a masthead light indicate in terms of placement and visibility?

A masthead light is required on vessels to indicate their presence at night. The correct choice highlights that a masthead light is positioned over the bow and provides visibility through a 225-degree arc. This positioning is crucial for ensuring that other vessels can recognize the masthead light from the appropriate angles, particularly from ahead to a point about 45 degrees on the starboard and port sides.

The 225-degree arc means that the light is visible not directly to the stern but primarily in front and to the side, which assists in collision avoidance during night navigation. The light must be white to be recognized universally.

The placement over the bow aligns with requirements for maintaining visibility and ensuring safe navigation. It signals effectively to other vessels that the boat is moving, as opposed to stationary lights, which would indicate the vessel is at anchor. This understanding of light placement and their respective arcs is essential for any captain to navigate safely at night.