The masthead light may be located at other than the fore and aft centerline of a vessel _____________.

The masthead light may be located at other than the fore and aft centerline of a vessel that is less than 12 meters in length because of specific regulations regarding smaller vessels' lighting configurations. Vessels under this length are often designed to be more maneuverable and less complicated, allowing for more flexibility in their lighting arrangements.

In these cases, allowing a deviation from the strict placement of the masthead light adheres to simplified standards meant to enhance safety while not overburdening smaller craft with stringent requirements that benefit larger vessels. Furthermore, as vessels increase in size, they typically have different lighting configurations that adhere to more strict regulations to ensure visibility and safety on the water. This understanding is reflected in maritime regulations, which recognize that smaller vessels can manage effective visibility through other means, allowing for some leniency.