What do white lights indicate on a vessel?

White lights on a vessel typically indicate the presence of a stern light or a masthead light. A stern light is positioned at the rear of the vessel and is visible from behind, while a masthead light is found at the top of the vessel's mast and shines forward. Both lights are essential for navigation and safety, helping to indicate the vessel's presence and direction to other mariners. In some cases, all-around white lights may also indicate that a vessel is anchored or aground.