Product Review: Sea Water Pro Mini water maker

The Sea Water Pro Mini (110-volt AC) water maker

One thing everyone told me I’d need in the Bahamas, especially in the Exumas, was a water maker. It was simply too difficult or too expensive to find fresh water for use on board. And it’s just such a pain in the ass to have to be rationing your water day in and day out. “Get a water maker,” they all said, “and you’ll enjoy cruising more.”

So, okay, I’ll get a water maker. To be honest, I’d been thinking about it for some time anyway. I mean: the whole point of escaping on a sailboat was independence—and how independent could you really be if you had to stop in every few days and buy water, THE most important resource for the human body? But installing a built-in water maker into Further wasn’t really feasible, both for space reasons and money reasons. There were, however, some self-contained, portable water makers—two, primarily—that could do the job. And I bought one of them.

I’d heard great things about the Rainman portable water maker for several years, but in the past year-plus I’d been hearing more and more about Sea Water Pro, a company out of Florida. Friends had one of their installed models and loved it, and another set of friends who’d cruised the Bahamas last winter said they had friends who had Sea Water Pro’s portable model and loved it. I’d heard nothing positive about either company’s 12-volt models, so I decided on a 110-volt, AC-powered model that I’d run via the inverter on Further’s electrical system. And after talking with the Sea Water Pro people at the fall boat show in Annapolis, I decided that was the water maker for me.

What sealed the deal was that the Rainman system consisted of two separate parts, each in a plastic case, while Sea Water Pro’s had everything in one case. That, and the fact that (at the time) the Sea Water Pro Mini was $1,500 cheaper than the Rainman model, made it a pretty easy decision. (It also helped that many of the parts such as filters for the Sea Water Pro were fairly standard and could be bought on Amazon.) I talked with the Sea Water Pro rep through the fall months as I made my way down the ICW and ultimately took delivery while I was in Brunswick, Georgia. I used it for the first time in February in the Exumas, and I’ve now made water double-digit times on board and feel qualified to draw a few conclusions.

The first couple of times I ran the water maker I simply plugged it into to my 110-volt electrical system and fired it up. And…voila! Making water…how cool! Except that I found that the water maker is, in fact, an energy hog—something I knew but something I’d been led to believe that my lithium batteries and solar panels could handle. Nope. Not even close. In fact, in my second water-making effort I damn near wiped out my batteries. It took a bunch of engine running afterwards to bring the batteries back up to full. That was a shocking lesson. A sailor on a neighboring mooring ball in Spanish Wells had the same machine and ran it off his electrical system with no problem. When I asked him what his boat had he said it was 900 amp-hours of battery capacity and 1,400 watts of solar-power generation. Yup, that’s a bunch more than my 600 amp-hours and 500 watts, and it makes a huge difference.

As a result, I learned to run Further’s engine while I make water. Doing so keeps the energy going to the water maker roughly equal to the energy the engine and alternator are sending to the batteries. So call it a wash, right? No, it’s not, because running the engine wastes fuel and it’s not good to run a marine diesel engine with no load (like a propeller driving a 27,000-pound boat, for instance)—and I can’t run the water maker while running the boat under power because the intake hose (with a lift pump at the end) doesn’t reach the water. And let’s not bring up the fact that the whole reason I sail is so that I don’t have to listen to an internal-combustion engine rumbling all the time. That’s just frustrating, man.

I found a discussion on Facebook on the Sea Water Pro unit and, not surprisingly (given it’s Facebook), the answers were all over the place. But my takeaway was this: Further’s electrical system is insufficient to power the Sea Water Pro Mini water maker—despite what I’d been led to believe. In hindsight, I should have bought the Honda generator I’d been thinking about; it could have powered the water maker and been a back-up for the boat’s electrical system when some of the various problems arose on this trip.

I’ve also found that the company’s claims that the Mini water maker could make twelve to fourteen gallons of water an hour are gross exaggerations. I’ve found that six to six-and-a-half gallons an hour is more realistic, and the guy on the neighboring boat in Spanish Wells concurred, saying the most he’d seen was seven gallons an hour. I’ve been in media a long time so I get marketing hype, but a full 2X difference between claim and reality? That kinda pisses me off.

The other drawback to the realistic capacity of the water maker is that, as with pretty much all water makers, you have to run clean water through the system before you put it away in order to keep the reverse-osmosis membranes lubricated. In the case of the Sea Water Pro Mini, that means filling a bucket with several gallons of purified water and then putting the intake hose into said bucket and running that water through the water maker and into the boat’s tank. It’s another 45 minutes to an hour of making water to fill the bucket just for for the cleaning process.

So at this point, I’m more or less running the water maker every few days for no other reason than to keep the membranes supple. They are not covered by the company warranty and, again, keeping the membranes happy is pretty much standard operating procedure for any water maker. I prep the system, fire up Further’s engine and turn on the Sea Water Pro Mini, which fills the bucket in about an hour. I then stop the water maker, put the intake into the bucket and run that water through the system and into Further’s tank—so that’s another bit of time. And of course there’s always a bit of water that the intake can’t get so that gets poured from the bucket into the tank after everything is shut down, but you never get all of that water actually INTO the tank.

So I spend an hour-plus on the process. I use an hour-plus worth of diesel and put an hour-plus worth of not-good strain on the engine. All to put a bit less than six gallons of water into my boat’s tank. And I do this every few days in order to keep the water maker’s core, the membranes, from drying up and rendering the unit useless. And I paid good money for the privilege.

What takeaways are there, then? Well…

Again, I should have bought that Honda generator. Doing so would have wiped out the price difference between the Sea Water Pro and the Rainman, but at least I’d also have a good generator that could have served other purposes.

And, frankly, for the price of the water maker, I could have filled up Further’s entire 100-gallon water tank more than 63 times—and that’s at the most expensive price for water I’ve seen on this trip. In most places water was a lot cheaper than that (meaning more than 63 fill-ups) and even in a few places (George Town, Black Point Settlement) water was free, you just had to schlep it to your boat. For another comparison: in George Town I could have had a full 100 gallons of water delivered to the boat and pumped into Further‘s tank thirty-five times for the price of the Sea Water Pro Mini. Throw in the additional money for the generator I should have bought and that’s even more that could have gone to buying water along the way.

Add in the price of diesel and the wear-and-tear to run the engine to power the water maker and the real cost goes up still more.

On top of that, I’ve been disappointed with the workmanship on the unit. The first time I used it, water leaked (albeit slowly) from two different bolts in the system. After trading text messages with the sales person (who contacted the owner of the company), I went ahead and tightened up those bolts and the leaks stopped. But what kind of quality control allows loose bolts to leave the factory? That has me worried about the longevity of the unit long-term.

Look, I think reverse-osmosis is an amazing technology. The fact that I can make tasty, drinkable water from everyday ocean water with the help of a machine that fits into one piece of carry-on-sized luggage is mind-blowing. And yes, having this water maker could save your life if you were ever stranded somewhere with no fresh water (but plenty of electricity). Sea Water Pro (and other companies as well) have done an amazing bit of engineering.

But the fact of the matter is that the Sea Water Pro Mini is not efficient enough for regular use on a cruising sailboat. When I return to the States I will take one of several courses of action: I’ll buy the Honda generator and keep the Sea Water Pro; I’ll look into adding still more battery and solar-generation capacity on Further so the electrical system can power the water maker; I’ll sell the Sea Water Pro and look into the Rainman model; I’ll sell the Sea Water Pro and install a built-in water maker on Further; or I’ll sell the Sea Water Pro and start carrying a lot more jerry cans on board to fill the tanks wherever and whenever I find fresh water.

In hindsight, I wish I’d saved my money and looked at other options. I may still have come back to the Sea Water Pro—in one of the configurations listed above or maybe another I can’t think of right now—but then again, maybe I would have gone an entirely different route. But I’d have saved a lot of money and wear on my boat’s diesel engine in the process. Lesson learned.


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