What navigation lights are required for an 18-foot powerboat?

The required navigation lights for an 18-foot powerboat include a red light on the left (port side), a green light on the right (starboard side), and a white light. This configuration is essential for ensuring visibility to other vessels at night and during periods of reduced visibility. The red and green lights designate the sides of the boat, indicating to other boaters the direction the vessel is heading. The white light, typically positioned at the stern or masthead, serves as an all-around light that indicates the boat's presence from various angles.

This lighting arrangement aligns with the regulations set forth in the U.S. Coast Guard navigation rules, which apply to powerboats of this size and help prevent collisions by making vessels more recognizable to one another in the waterway, thus enhancing safety on the water. The other options incorrectly include combinations of lights that do not conform to these standard navigation requirements.