When a vessel is over 50 meters, what lighting configuration is required for pilot vessels?

The correct choice regarding the lighting configuration for pilot vessels that are over 50 meters in length is white on red all-around lights. According to the International Regulations for Preventing Collisions at Sea (COLREGs), pilot vessels under way must display this specific lighting to provide clear and visible identification to other vessels, indicating their operational status as pilot boats.

By using white on red all-around lights, pilot vessels can signal their role in providing navigational assistance, especially in busy or congested waterways. This lighting configuration helps other mariners to recognize the vessel's purpose and ensure safety during navigation. The distinct use of a white light combined with red is crucial in avoiding confusion with other vessel types and ensures compliance with the regulations set forth for safe maritime operations.

In summary, the requirement for pilot vessels over 50 meters to have white on red all-around lights is rooted in enhancing visibility and safety in maritime operations, allowing other vessels to effectively recognize their function in the maritime environment.