Nav lights for motor vessel underway less than 12 meters: which lights are required?

• A. Masthead light and sidelights
• B. 360 white light on stern, and port and starboard side lights
• C. Stern light only
• D. Sidelights only

Answer: (B)

For a small motor vessel underway at night, the lights are set up to show your presence and orientation to others without needing complex gear. A white light that shines all around from the stern makes the boat visible to ships approaching from any direction behind you, while the red and green sidelights show which side is which and help others determine if you’re crossing, meeting, or being overtaken. For vessels under 12 meters, a masthead light isn’t required, so the combination of a 360-degree white light on the stern plus port and starboard sidelights satisfies the rule and keeps the boat clearly visible from all angles. Having only a stern light or only sidelights would leave gaps in visibility, and adding a masthead light isn’t necessary for this size.