If you have ever been on the water at night and wondered if the marine navigation lights you see are from an approaching or fleeing vessel, or if the vessel is a fishing trawler or super tanker, then LIGHTrule™ is for you. Excellent aide for navigation classes and Coast Guard exams. Identifies all COLREGS60 Light configurations15 Day shapesActual view of vessel for port, starboard, bow & stern lightsVisual guide for horn signalsMagnifying lens for clear readability of definitionsDurable plastic construction