If you see a red a green and a white light on another boat what?

If you see a red light, a green light, and a white light on another boat, it indicates that the boat is facing you and is likely under way. The red light signifies the port (left) side, the green light signifies the starboard (right) side, and the white light is typically a stern light. This configuration helps determine the boat's orientation and direction of travel. Always maintain a safe distance and be aware of navigation rules.