How many masthead lights must a 50-meter power-driven vessel exhibit?

A 50-meter power-driven vessel is required to exhibit two masthead lights when under way at night. This regulation is part of the International Regulations for Preventing Collisions at Sea (COLREGs), specifically under Rule 23, which outlines the lights and shapes for power-driven vessels.

The reason for displaying two masthead lights is to enhance visibility and ensure that other vessels can easily identify the size and type of the ship from a distance. The two masthead lights are positioned vertically, with the upper light being higher than the lower one. This configuration not only aids in the vessel's identification but also minimizes the risk of collision by providing adequate warning to other vessels about its presence, especially in dark conditions or poor visibility.

Vessels shorter than 50 meters are typically required to show only one masthead light, which is why a single light is insufficient for vessels of this size. Thus, for a 50-meter power-driven vessel, two masthead lights are essential for compliance with maritime regulations, ensuring safe navigation at night.