What is indicated by two white lights displayed on a vessel?

The presence of two white lights displayed on a vessel indicates that the vessel is engaged in a short tow, specifically when the tow is less than 200 meters in length. This configuration is part of the navigation rules established to aid in the safe operation of vessels by ensuring that their intentions are clearly understood by nearby vessels.

The use of lights to signify particular vessel actions is crucial for avoiding collisions at sea, especially in low visibility conditions. In the context of navigation, understanding these light signals allows mariners to assess the situation quickly and act accordingly.

In contrast, an anchored vessel typically displays one or more anchor lights or a combination of lights that differ from two white lights. Similarly, a long tow would require the display of additional lights to indicate the length of the tow, and draft limitations do not have a specific visual signal represented by lights. Thus, the configuration of two white lights is specifically designated for signaling a short tow.