What is the purpose of a vessel's sternlight?

A vessel's sternlight is specifically designed to be seen from behind the vessel. This light provides critical visibility to other vessels approaching from the rear, helping to enhance navigation safety, especially at night or in low-visibility conditions. The sternlight serves as an important navigational aid, allowing operators of other boats to determine if a vessel is moving away from them or toward them, thereby reducing the risk of collision.

In the context of navigation regulations, sternlights must be placed in a specific position on the vessel to ensure they are visible from an appropriate distance. This not only helps in identifying the presence of the vessel but also its direction of travel, which is crucial for maintaining safe distances between vessels on the water.

The other options do not accurately describe the function of a sternlight. For instance, a vessel's speed is not indicated by its sternlight; rather, speed is determined by other factors such as the engine power and the hull design. Similarly, the vessel’s position from the front would be indicated by the bow light, not the sternlight. Lastly, a vessel's destination is typically conveyed through communication, signals, or navigation aids—not through a sternlight.