When we were originally thinking this over, I was thinking the same as you: a high capacity AC driven unit. Well, we ended up going in a different direction and the boat we bought already had a Spectra Newport
800 (16 gph, 12 volt). I was suspicious about it, particularly about Spectra's habit of using lots of proprietary parts
, expensively priced.
Well, after a cruising year of experience with it, I'm really happy with it. The other comments about them being happier when run often is spot on. Plus, when we've been places where the water was brackish and muddy (and I didn't want to run it), the autoflush feature is very, very nice. Keeps the watermaker happy without having to pickle it. Not only is pickling a hassle, every time you do it, you're doing slight, though accumulating damage to the membrane.
The energy consumption
of the 12 volt Spectra is quite reasonable. We also thought that we'd just run the gennie and take care of all those high power needs at the same time. Turns out we didn't do that nearly as often as we thought we would. But, the solar panels
did enough to pretty much keep up with those needs and then, we didn't have to use the diesel
or put up with the noise
. Also, if you do go with an autoflushing model (which I recommend) it will take care of itself even when you're off the boat, so long as it has both enough power and enough water in your tanks
to do the flush. Mine takes 6 gallons per flush. We've been off the boat for as long as 3 weeks and the autoflush kept everything OK.