I've replaced my all my internal lights, the mast head and tri-colour with LED's from Jeff at Replacement LED bulbs for your existing boat fixtures
and was very pleased. Had the mast lights switched on while I was up top as I didn't fancy two trips up a day, they worked perfectly and no noticeable heat problems, there is a lot of space for cooling.
The internal lights are high output 120 lumen "light hammers" and they certainly get warm, they do have a heat sink, but are much cooler than the 10w power hungry halogens they replace.
No affiliation with the Company other than being a pleased customer.
Who thought it was a good idea to put halogens on yachts ? fluorescent is a much better, more battery friendly solution, but LED technology seems to be moving at such a pace hopefully halogen bulbs will be one for yacht design history.