SM-3 SOLAS Lifebuoy Marker Light The SM-3 is a high intensity LED strobe which provides 360 visibility for approximately 2 miles. This compact yet durable marker light facilitates rescue by automatically activating and beginning to strobe when in the water, working for over 40 hours at 30C 86F or over 24 hours at -1C 30F. Perfect for commercial marine, petro-marine, cruisers, and any other application needing a reliable Crew Overboard Marker COB light, the SM-3 floats upright in all conditions,