In what scenarios is a vessel required to show anchor lights?

A vessel is required to show anchor lights when it is at anchor in anchorage areas. This requirement is outlined in the International Regulations for Preventing Collisions at Sea (COLREGs), which mandate that vessels at anchor must display specific lights to indicate their status to other vessels. This is crucial for safety because it helps prevent collisions by allowing other vessels to see the anchored vessel and understand that it is not underway.

When a vessel is anchored, it typically displays a white light or a combination of lights that signify it is not moving. This enhances visibility during nighttime or poor visibility conditions and informs approaching vessels of its presence.

In contrast, when a vessel is at dock, it may not be required to show anchor lights, as the need for lights depends on its operational status. Similarly, while towing or maneuvering, different lighting configurations are needed to communicate the activity of the vessel, but they do not require the specific anchor light configuration that is mandated for vessels at anchor.