http://www.orcagreen.com manufactures and sells U.S.C.G approved LED navigation lights
check out the trianchor strobe masthead light
http://www.svhotwire.com sells LED navigation lights (not U.S.C.G. approved) and other marine equipment
LED lights make sense from the standpoint of lower energy consumption, smaller wire size, less conductor weight aloft, longer bulb life, less prone to shock load failures: Public transportation, commercial vehicles are converting over to LED, fewer of these vehicles are being supplied these days with incandecent bulbs.
We go through literally cases of Duracell batteries every year in our flashlights,rechargable batteries lack copasity, as a result have been trying to convert over to LED lights. We purchased a number of LED flashlights, single bulb, multi-bulb, difused and focused beamed, AA and D celled lights, thus far, we are less than satisfied with the LEDs ability to illuminate dark engine room spaces and have gone back to using Xenon bulbs for best visibility.
Case in point: I was playing around with a new head lamp made by Cyclops, it has 3 LED and one Xenon bulb. It has four settings with the push of a button, 1,2,3 illuminates up to 3 LED bulbs, selection 4, turns off the LED and illuminates a Xenon bulb. With 3 LEDs illuminated, we have soft blueish-white light 2’ from the lamp, target detail is vague at best, setting 4, Xenon only, is extreamly bright yellow tinted light where detail is much easier to see, still not great, but it works.
Our experience with LED lights is most of the light is difused within several feet from the source,light reaching the target area is so difused detail is hard to see.
Number of LED bulbs in a light has a significant effect on projection and visibility, take public transportation for example, a typical city buss stop/turn light will have as many as 48 LED bulbs in a single 4" light. There is no question about it, with 48 bulbs x 4 light, when a bus stops, the entire back of the bus light lights up with extreamly bright light; you still can’t read by it, but you know the bus is stopping. If you can read by it, then may be you should have stopped sooner 
At the 2NM USCG visibility rating for navigation light, the LED just might work, all light, weather incandecent or LED, are diffused at 2NM.
Guess this means my kerosene navigation lamps are obsolete? not likely.
Marty Chin