I vote for LED. I replaced all of mine. I went from the small aquia signal 25 to a 40 with led bulbes. I cant under stand why the boat makers put the small marble size light on. You can hardly see them on a clear night much less with weather. You can see me clearly now. Now much brighter with much less power If you go led replacement bulb, make sure you match the color red led for red lense green led for green lense or use clear. you get funky colors if you use a white led under a colored lense. Not all sail boats have a tricolor mast head light. Be sure to figure the amp load and use proper size wire. I did call the Coast Guard about my lights and was told to go as large as I liked, that most installed were the minimum size required. But larger was fine.
GO BIG GO BRIGHT