Which light has an arc of visibility of 112.5 degrees and can be seen from the head to 22.5 degrees abaft the beam?

The correct choice indicates a light that is designed for specific visibility in nautical situations. In maritime navigation, the side light is positioned to illuminate an arc of visibility that extends 112.5 degrees. This light is essential for vessels to visually communicate their position and orientation to other vessels.

The side light is mounted on the port (left) and starboard (right) sides of a vessel, enabling it to be seen from directly ahead and extending back 22.5 degrees abaft the beam on each side. This configuration allows for effective visibility and identification of the vessel’s heading. When a side light is visible to another vessel, it provides crucial information about which side the observing vessel is looking at—therefore aiding in navigation and collision avoidance.

In contrast, masthead lights and stern lights have different visibility arcs and purposes. Masthead lights serve a full 225-degree arc and are used primarily to indicate the presence of a vessel in the water, while stern lights illuminate the area directly behind the vessel. The towing light has its own specific characteristics for vessels engaged in towing operations. Understanding these distinctions is vital for safe navigation and compliance with the COLREGs.