What is the minimum range of a masthead light on a vessel that is 50 meters or more in length?

The minimum range of a masthead light on a vessel that is 50 meters or more in length is indeed 6 miles. This requirement is outlined in the International Regulations for Preventing Collisions at Sea (COLREGs), specifically in Rule 21 for the types of lights to be carried by vessels. The purpose of these lights is to indicate the position and heading of a vessel to others at sea, especially during the night or in conditions of reduced visibility.

A vessel measuring 50 meters or more is required to have a masthead light with a range of at least 6 miles to ensure that other vessels can see it well in advance. This helps in preventing collisions and promotes safety by ensuring that the presence and direction of larger vessels can be identified from a significant distance.

Lesser ranges, such as those mentioned in the other options, apply to either smaller vessels or specific types of lights and conditions. However, for a vessel of this size, the standard of 6 miles is essential to maintain adequate navigational safety standards on the water.