What component is used to indicate the position of a vessel at night?

The navigation light is specifically designed to indicate the position and heading of a vessel at night or during periods of reduced visibility. These lights follow regulated patterns depending on the type of vessel and its activities. For example, different colors and combinations signify a vessel's orientation; a red light indicates the port side, while a green light signifies the starboard side. These lights help other vessels determine the direction the vessel is traveling and avoid collisions, promoting safe navigation in dark conditions.

While other lighting options like anchor lights, masthead lights, and deck lights serve specific purposes—such as indicating when a vessel is anchored, providing visibility for the crew on deck, or signaling the highest point of the vessel respectively—they do not establish the vessel’s directional position in relation to other vessels like navigation lights do.