What is the arc coverage of a side light?

The coverage of a side light is critical in ensuring proper visibility and identification of vessels during nighttime navigation. A side light is specifically designed to illuminate the area where a vessel is located while also indicating its direction of travel to other vessels. The correct arc coverage for a side light is 112.5 degrees.

This 112.5-degree arc is divided into two segments: it covers 22.5 degrees forward of the beam (the sides of the vessel) and extends 90 degrees aft (to the rear). This configuration enables the side light to be effective in helping nearby vessels determine the heading of the vessel displaying the light, thereby assisting in preventing collisions.

Understanding this arc coverage helps in recognizing how vessels are equipped to communicate their position and direction at night, ensuring safe navigation through proper signaling. Other options like 90 degrees, 135 degrees, and 180 degrees do not match the established standards set forth by the COLREGs regarding side lights, which specifically mandate the 112.5-degree coverage to create a unified understanding among mariners.