A vessel displaying only a white light is most likely which condition?

A vessel displaying only a white light is most likely which condition?

• A. The stern
• B. A vessel at anchor
• C. A vessel at anchor or stern light or manually propelled
• D. A sailing vessel

Answer: (C)

White lights are used for several specific signals, so seeing only a white light typically points to a vessel that isn’t displaying the full set of navigation lights. The best interpretation is that the vessel is either at anchor (showing the white anchor/360-degree light), or it is displaying a stern light (a white light located at the stern), or it is a manually propelled craft (rowboat or similar) which may carry only a white light to indicate its presence. A vessel that is sailing or powered and underway would normally show other lights in addition to white, such as sidelights (red and green) and, if appropriate, a masthead light. So a single white light fits the listed conditions of being at anchor, showing a stern light, or being manually propelled, rather than indicating a sailing vessel or a normally underway vessel.

White lights are used for several specific signals, so seeing only a white light typically points to a vessel that isn’t displaying the full set of navigation lights. The best interpretation is that the vessel is either at anchor (showing the white anchor/360-degree light), or it is displaying a stern light (a white light located at the stern), or it is a manually propelled craft (rowboat or similar) which may carry only a white light to indicate its presence.

A vessel that is sailing or powered and underway would normally show other lights in addition to white, such as sidelights (red and green) and, if appropriate, a masthead light. So a single white light fits the listed conditions of being at anchor, showing a stern light, or being manually propelled, rather than indicating a sailing vessel or a normally underway vessel.