When we bought our catamaran (usvi/bvi) it had a non functioning Pur 80. Normally 2 of us, with 120 gal/h20. Guests would come and visit and I'd become a water nazi. it was always available and would be the only reason we'd hit the water/fuel dock every 14 days (no guests) and 10 with. Our boat is for sale and having a low production, non working watermaker is better than not having one. Down island it isnt needed. Cruz Bay/St John, Red Hook/St Thomas, Sopers Hole, Nanny Cay, Roadtown, Fat Hogs, Marina Cay, Scrub Island all on Tortola, Leverick Bay and 3 or 4 other places in North Sound, then Spanishtown, all on Virgin Gorda. There are other places on island also. Point is, its there. Then there was the time we were charged for more water than we held, 140 gallons. I laughed at the water provider and told him our water tanks must have grown. he didnt laugh.
As a boat seller, If I had it to do again, I'd have left it on the boat.