Which situation requires a vessel to display two all-round red lights, sidelights, and a stern light?

Which situation requires a vessel to display two all-round red lights, sidelights, and a stern light?

• A. Vessel making way unrestricted
• B. Vessel underway in harbor
• C. Vessel unable to maneuver due to exceptional circumstance
• D. Vessel anchored

Answer: (C)

This situation reflects a vessel not under command, meaning it is unable to maneuver as required by the Navigation Rules due to exceptional circumstances. To signal this to other vessels, it displays two all-round red lights in a vertical line. Those red lights are shown in all directions to warn others that the vessel cannot take action to avoid a collision. If the vessel is underway, it also keeps the standard running lights—sidelights (port red and starboard green) and a stern light—so others can gauge its direction and relative position. The combination of two red all-round lights plus the sidelights and stern light plainly communicates “I’m moving but cannot maneuver to avoid you.” The other scenarios don’t involve a vessel that cannot maneuver, so they don’t require this distinctive red-light setup.

This situation reflects a vessel not under command, meaning it is unable to maneuver as required by the Navigation Rules due to exceptional circumstances. To signal this to other vessels, it displays two all-round red lights in a vertical line. Those red lights are shown in all directions to warn others that the vessel cannot take action to avoid a collision. If the vessel is underway, it also keeps the standard running lights—sidelights (port red and starboard green) and a stern light—so others can gauge its direction and relative position. The combination of two red all-round lights plus the sidelights and stern light plainly communicates “I’m moving but cannot maneuver to avoid you.” The other scenarios don’t involve a vessel that cannot maneuver, so they don’t require this distinctive red-light setup.