Re: LEDs afloat
As semiconductor devices, LEDs will be more sensitive to reverse voltage and overvoltage than some of the other lights, so I'd expect them to be more easily damaged by lightning strikes. Just like all the other electronics on a boat.
But having said that, I'd still use LEDs because a good lightning strike can also blow out every kind of light and appliance known to man, and they routinely do that even in homes. You could probably take steps to harden the lighting wiring so it was less likely to get an inductive surge from a strike, or less likely to carry a strike, but lightning is such a damn pigheaded creature, that you could probably spend less by just changing the blown LEDs. Along with everything else the lightning struck.