What lights should a vessel not under command (NUC) exhibit when at anchor?

A vessel not under command (NUC) is required to exhibit specific lights to ensure it is visible to other vessels and to communicate its status. When a vessel is at anchor and classified as NUC, it must show normal anchor lights appropriate for its size. This typically includes a white light situated at the stern and a second white light at the bow, ensuring that other vessels can identify its position clearly, particularly in the dark.

The designation of 'not under command' is crucial, as it signifies that the vessel is unable to maneuver due to exceptional circumstances. By exhibiting the appropriate anchor lights, the vessel provides essential information to nearby mariners, helping to prevent collisions and promoting navigational safety.

Other options do not correctly represent the necessary signaling for a NUC vessel at anchor. For instance, red and white lights, flashing amber lights, or flares do not align with the COLREGs regulations for displaying lights when at anchor. Thus, the proper indication for a NUC vessel at anchor is to use the standard anchor lights relative to its size.