What is the night signal for a vessel restricted in its ability to maneuver?

• A. Red lights only
• B. Green lights and a ball
• C. Red lights plus the day shape ball-diamond-ball in a vertical line
• D. White lights arranged in a square

Answer: (C)

Vessels restricted in their ability to maneuver announce their status with a specific signal set so other ships know to give them extra room. At night, the signal is three all‑round lights in a vertical line: red at the top, white in the middle, red at the bottom. That red–white–red arrangement clearly communicates the restriction to maneuver. The daytime counterpart is a vertical line of day shapes: ball, diamond, ball. So the best answer matches both the night lights and the corresponding daytime shapes, indicating the vessel’s restricted maneuverability in all conditions. Other options don’t fit the standard signals for this situation.