How should a non-power-driven vessel exhibit itself at night?

A non-power-driven vessel, such as a sailing boat, must adhere to specific rules regarding navigational lights at night, as stipulated in the COLREGs. The appropriate way for such vessels to exhibit themselves is to display sidelights (red on port side and green on starboard side) and a stern light. This configuration allows other vessels to discern the direction the sailing vessel is heading based on the color of the lights displayed. The sidelights indicate the vessel's port and starboard sides, while the stern light shows that the vessel is moving away from an observer positioned aft.

This combination of lights is critical for collision avoidance during the night and in reduced visibility conditions, as it enables other vessels to gauge not only the presence of the non-power-driven vessel but also its heading.

The other options do not provide the correct visual indicators for a non-power-driven vessel: displaying an all-round white light is used for different types of vessels or specific situations (like an anchor), while a single red light does not communicate enough information for safe navigation. A flashing light might confuse other vessels or indicate a different situation, such as an emergency or a vessel engaged in specific activities.