A vessel engaged in diving operations during restricted visibility or at night must display which all-around light combination?

A vessel engaged in diving operations during restricted visibility or at night is required to display a specific combination of all-around lights to ensure visibility and indicate its activities to other vessels. The correct combination of lights is red, white, red.

The red lights indicate that the vessel is engaged in diving operations, signaling to other vessels that they should keep clear of the area for safety. The white light serves as a warning that the vessel has an active operation in progress, allowing other mariners to understand the nature of the vessel's activities. The arrangement of red, white, and red lights provides a clear visual cue about the vessel's status, making it evident that it is not just stationary but involved in diving, which inherently carries risks for both the divers and nearby vessels.

The other light combinations listed do not appropriately indicate a diving operation. For instance, green lights are typically associated with vessels that are under sail or conducting different types of operations and do not convey the necessary warnings to indicate diving activities. Therefore, the specific combination of red, white, red is crucial for communicating the vessel's operational status effectively to maintain safety on the water.