The US Coast Guard posted an alert regarding unapproved lights on recreational and commercial vessels. Particularly since the advent of light emitting diodes (LEDs), lights in addition to required navigation lights are being installed on vessels. Navigation lights must meet regulatory requirements relating to intensity, color, and location. All other lights on vessels must not be mistaken for navigation lights, not impair the visibility or distinctive character of navigation lights, and not interfere with the operator’s ability to maintain a proper lookout. Safety Alert 10-15
http://www.uscg.mil/hq/cg5/cg545/alerts/1015.pdf