Which combination of lights indicates a vessel is at anchor?

A vessel at anchor is required to display specific lights to ensure its visibility and to communicate its status to other vessels. The appropriate combination of lights in this case is a single white light visible all around the horizon, which is often referred to as a 360-degree white light.

This light serves as an indication that the vessel is not under way and is effectively moored in a specific location. The inclusion of red lights typically signifies a vessel's port side or other navigational signals but is not relevant to the indication of anchoring. Therefore, the correct identification of a vessel at anchor is solely represented by the 360-degree white light. This regulation helps to prevent collisions and informs others of the vessel's stationary status in the water.