Hella do nice stuff, used by OEM boat builders like Fair/Sunseek/Prin, for use in side deck type locations
But if you want them underneath a bathing platform the Hellas wont do as they're not intended to be submerged or blasted by a wake. you'd need the highest level of waterproofness, as used for u/w lights. In which case www.lumishore.com drivelights might be best