What vessel exhibits an all-round white light forward and aft?

A vessel exhibiting an all-round white light both forward and aft is displaying its anchorage status. According to the International Regulations for Preventing Collisions at Sea (COLREGs), when a vessel is at anchor, it must show an all-round white light to indicate its position. This light serves as a signal to other vessels in the vicinity, helping them understand that this vessel is not under way and is anchored.

While other types of vessels have specific light configurations that signify their activities—such as vessels underway showing various combinations of colored lights depending on their size and operational status—a vessel engaged in fishing may show different lights and shapes to indicate its activity. Moreover, a vessel in distress typically displays specific light signals distinct from those used by anchored vessels.

In summary, the all-round white light both forward and aft specifically identifies a vessel at anchor, making the chosen answer accurate in aligning with the COLREGs standards.