You may need some bedding to prevent electrolysis, but these are holes drilled through your hull with no seacock to shut down a failure. They should be bed in the nastiest, most permanent goop you can possibly conjure up.
The prior owner of our boat had them installed. They make me nervous and boy do they suck up some power when they are on!! In any case, they are completely useless around here. Even in the relatively clear water of Cuttyhunk, I haven't been able to see anything. The grass bed is only 7 or 8 feet below the lights and its indistinguishable. Unless in truly crystal clear water of the Caribbean, they are a waste of money, IMO.
If you just want the "glow" around the boat at the dock, no other sailboat crew is going to speak to you.