What colors are the side lights on a vessel, and which side do they indicate?

• A. Green on starboard side; Red on port side.
• B. Green on port side; Red on starboard side.
• C. White on starboard; White on port.
• D. Yellow on both sides.

Answer: (A)

Side lights identify which side of the vessel is toward you, helping others judge spacing and passage. The red light is on the port (left) side, and the green light is on the starboard (right) side. This arrangement lets nearby boats immediately tell whether you’re on the left or right and plan a safe pass. So the description that matches this standard is red on the port side and green on the starboard side. White or yellow lights serve other purposes and aren’t the sidelights described here.