I have been using LED lighting on an old Macwester yacht.
The reason I have used them is the power saving and coupled with a solar charging panel I am hoping i will not have any lighting problems.
AS per the very first post of this thread there was mentioned mast light
This is one i made earlier. my Mast all round navigation light and Anchor light...
Formed with Polyester resin and formed in a glass jam jar.
I had to break the class jar when it had set solid.
Just needs a quick polish now with T Cut or a g3 cutting compound thae same stuff they buff car paintwork with..
also I have been working on Navigation lights that I can insett to the rubber fendering
These are water resistant strips .with a self adhesive backing strip.
Easy to cut to size and fit.
And a lot of power saved.