Which vessels are required to display masthead lights?

Masthead lights are an essential component of navigation safety, specifically designated for vessels that are power-driven and underway. These lights are displayed on the foremast or, if there is no foremast, at the highest point of the vessel's structure. The masthead light serves to indicate the presence and heading of the vessel to other mariners, thereby helping to prevent collisions at sea.

Power-driven vessels are defined as those that are equipped with machinery to propel them, which is a fundamental consideration in maritime navigation rules. When these vessels are in motion, having a masthead light illuminated is critical for ensuring that their position is known to nearby vessels, particularly at night or during periods of low visibility.

Other types of vessels may not be required to display a masthead light in the same manner. For instance, sailing vessels may be equipped with different lighting configurations depending on whether they are under sail or using auxiliary power. Fishing vessels at anchor generally follow a different lighting protocol, primarily displaying anchor lights instead. Lastly, non-power-driven vessels, such as those solely under sail, will not typically display a masthead light during the periods that they are not using auxiliary power.

Thus, the requirement for power-driven vessels underway to display masthead lights is a specific