What is the minimum visibility of all lights on a vessel of 50m or more in length?

The correct answer is based on the regulations outlined in the International Regulations for Preventing Collisions at Sea (COLREGs). For vessels of 50 meters in length or more, the minimum visibility for all lights is indeed set at 6 miles. This requirement is established to ensure that other vessels can detect larger ships at a safe distance, thus promoting safety at sea and helping prevent collisions.

Larger vessels are subject to stricter visibility requirements due to their potential inability to maneuver quickly and the increased risk they pose in congested waters. The visibility range enables other mariners to assess the position, course, and speed of the larger vessel from a distance, giving them ample time to take necessary actions to avoid close encounters or collisions.

This regulation emphasizes the importance of being seen by other vessels, especially in busy shipping lanes or during periods of reduced visibility, such as fog or heavy rain.