I can supply LED spotlamps, in 24 & 27W all the way up to 72W (get a bit pricey though). The 24W pull 2 amps each and are five times brighter than 55W halogen lamps at half the power drain. Same as HERE, although I am happy to supply and post to any marina or other local place for you. The 24W are very thin at under an inch, with the 27W being the same housing, just 50% thicker again for the extra heatsink. They are solid aluminium and glass and really take a beating. I can happily pressure wash mine without them breaking. They are happy working on 9v-30v.
These are a pair of 24W's showing the beam and range. Yours for just under £30each, or around £55 for a pair (offhand).