When only white and red lights are visible, you are approaching the port side of a powerboat and thus you should give way to your starboard side.
Explanation;
-The red and green lights are called sidelights (or combination lights) because they are visible to another vessel approaching from the side or head-on. The red light indicates a vessel's port (left) side; the green indicates a vessel's starboard (right) side.
-When only a white light is visible, one may be overtaking another vessel. Give way to either side. Additionally, when only a red light is visible, you are approaching the port side of a sailboat.
