What are "running lights" used for on a vessel?

Running lights are crucial safety features on a vessel that serve specifically to indicate the ship's position and heading. This is essential for preventing collisions while navigating in the dark or in conditions with poor visibility. These lights convey a wealth of information to other vessels regarding which direction the ship is heading; for example, a green light on the starboard side and a red light on the port side help identify the orientation of the vessel to others. Thus, running lights play a vital role in maritime navigation safety, ensuring that vessels can visually recognize one another and make informed decisions to maintain safe distances and avoid accidents.

The other options do not accurately represent the primary function of running lights. Enhancing speed, illuminating cargo areas, and signaling for distance are not the intended uses of running lights, which are fundamentally about visibility and collision prevention.