What is the requirement for visibility of masthead lights on a vessel?

Masthead lights are designed to indicate a vessel's presence and heading to other vessels, and their visibility requirements are important for maintaining safety at sea. The requirement for masthead lights specifies that they must be visible for 225 degrees, which means they should provide coverage from directly ahead to a point 22.5 degrees abaft the beam on either side of the vessel. This configuration allows for adequate visibility to oncoming vessels and helps in preventing collisions by clearly indicating the direction in which the vessel is headed.

The 225-degree visibility ensures that the light can be seen from most angles other ships may approach, which is crucial during night operations or in poor visibility conditions. Hence, this requirement plays a key role in the effective functioning of the International Regulations for Preventing Collisions at Sea (COLREGs).

The other options, while related to visibility, do not accurately describe the specification for masthead lights. Visibility up to 360 degrees is not necessary for masthead lights specifically, as other navigational lights fulfill roles in different sectors. Additionally, while masthead lights do have a range requirement in terms of visibility distance, stating specifically 4 miles pertains to larger vessels under certain conditions, thus not reflecting the specific degree visibility. The assertion that mast