Final answer:
The sidelight on the starboard side of a vessel is green.
Step-by-step explanation:
The sidelight on the starboard side of a vessel is green.
In boating, sidelights are used to indicate the direction a vessel is traveling at night. The sidelight on the starboard side, which is the right side when facing forward, is typically green. The sidelight on the port side, which is the left side when facing forward, is typically red. These lights help other vessels determine which direction a boat is moving and prevent collisions.