ed50,

The reason for the Red / Green running lights being recessed in the hull is to keep them from getting damaged while docking etc.

All docks are not all the same hight in San Pedro so sometimes the Bow of the boat can end up under a dock due to high wind conditions etc. theirfore causing a protruding light to be damaged or knocked off.

Over in Britain, my brother, brother in law, a good friend and my 2nd cousin's 3rd wife all damaged their running lights by hitting docks with a boat.