Red over red with a 360 white light indicates which condition?

• A. Vessel underway
• B. Vessel not under way
• C. Vessel has run aground
• D. Vessel anchored

Answer: (C)

This light pattern shows three all-round lights in a vertical line: red over a white over red. In COLREGS, that arrangement means the vessel is restricted in its ability to maneuver. The red lights indicate limitations placed on the vessel’s movements, and the central white light confirms visibility in all directions. The white in the middle is specifically a 360-degree signal, ensuring the pattern is recognizable from any direction.

This pattern is distinct from a simple underway vessel (which would show the standard forward masthead and side lights along with a stern white light), a vessel not under command (two red lights, no white), or a vessel at anchor (a single white light visible 360 degrees). The key idea to remember is red-white-red in a vertical stack signals restriction in maneuverability due to the vessel’s operations (like towing, dredging, or similar work).