What type of light is required to be 360 degrees?

Answer: D — All-around light

An all-around light is designed to illuminate the area surrounding a vessel in all directions, providing a continuous signal that can be seen from any angle. This type of light is especially important for vessels that are at anchor or not underway, as it ensures that their presence is clearly visible to other vessels approaching from any direction. The 360-degree coverage is crucial in preventing collisions and maintaining safety in congested waters. This is distinct from other types of lights, like side lights or stern lights, which have more specific directional responsibilities and are only visible from certain angles.