Re: Water makers.
Not familiar with it but my first thought is is it a 'purifier' or a 'desalinator'?... very different job description to clean up suspect tap water vs removing salt from sea water.. I suspect a Costco unit would simply be for purifying domestic fresh water.
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
1984 Fast/Nicholson 345 "FastForward"