How is an anchored vessel indicated?

An anchored vessel is indicated by displaying a white all-around light, which is a requirement under the COLREGs rules. This light must be visible from all angles (360 degrees) as it signifies that the vessel is not under way and is safely anchored.

The use of a white all-around light helps other vessels recognize the anchored status of the ship, which is critical for navigation safety and avoiding collisions in crowded waterways or poor visibility conditions. This light must be shown at a height that ensures it can be seen from a distance, aligning with the regulations that aim to enhance safety at sea.

Regarding the other options, they do not conform to the guidelines for indicating an anchored vessel, as they are designated for different situations or types of vessels.