In what scenario should a boat display an all-around white light?

An all-around white light must be displayed by a boat when it is at anchor to ensure visibility to other vessels, indicating its presence and position. This is a crucial safety measure during nighttime or in conditions of reduced visibility, as it helps prevent collisions by making the anchored vessel detectable to approaching boats.

Displaying an all-around white light serves as a signal that the vessel is not in motion, allowing other mariners to navigate safely around it. It is particularly important in waterways where traffic may be high or during nighttime operations, aligning with maritime navigation rules designed to enhance safety on the water.

In contrast, while underway, vessels typically use different lighting configurations suited to their situation, such as sidelights and a stern light, to indicate movement and orientation. During the day, visibility is often sufficient without relying solely on lights, and fishing boats also have specific light requirements that differ from those at anchor.