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When outfitting ZTC, a huge decision for us was whether or not to install a watermaker on board. The decision to ultimately do so was based upon two things:

  1. the fact that ZTC only carries 47 gallons of water in her main tank
  2. our desire to explore out-of-the-way islands and avoid visiting marinas

When shopping for systems, we opted to purchase a DC powered Katadyn 80E, largely because of how robust and simple to use it was reported to be. I will go on record to say that we have been very happy with our decisions, both to install a watermaker in the first place and with our choice of units. We have had very little difficulty with the Katadyn system and we have never had to jerry jug water to and from a shoreside source.

All that said, if I was going to do it all over again, I probably would choose another system. The 80E specs say that it has a capacity of 4 gallons per hour and that it draws 8 amps. While it can run off our batteries, an 8 amp draw is a fair amount. Unless we run it when the sun is unobstructed and high in the sky, we frequently find ourselves running our Honda generator to keep the voltage up (watermaker motors, or motors in general, don’t like running in low-voltage situations). Of course, if we had more solar panels, perhaps that situation would be different but given our current setup, that is how we operate. It’s OK, but my current thoughts are that if I’m going to run a generator, I might as well invest in a higher-output model. Which leads us to the systems made by CruiseRO.

Note: We are in no way sponsored by CruiseRO nor have we received any discount on the purchase of our watermaker described below.

With potentially 8 people on board the Leopard, 3/4 of whom will likely not have the water discipline that Rebecca and I do, we definitely will need a system that produces more than 4 gallons per hour. During my research, I stumbled across CruiseRO’s 40GPH system which is designed to run off a Honda 2000 generator, not the ship’s batteries (see bottom of post for clarification from CruiseRO). Some might consider that a disadvantage but as I said, much of the time we ended up running the generator while our 12V model was on anyway. This unit is spec’d to produce 40 gallons per hour though, not four, and with charter guests on board, being able to quickly replenish our water tanks will not just be a luxury, it will be a requirement!

There are three other big pluses:

  1. the price is right
  2. the units get great reviews
  3. the manufacturer, a cruiser himself, reportedly gives incredible service

While I have not yet got my hands on the watermaker, it has been delivered to our freight forwarder in Miami and is presently awaiting transport to St. Maarten where we will pick it up. Having installed a watermaker before, I’m pretty confident that I’ll be able install the system on the 4600 in a professional manner, just as I did on ZTC. While we will still not encourage our guests to take Hollywood showers 3 times per day, I’m pretty confident that we’ll be able to keep up with demand. A clean guest is a happy guest! 🙂

A minor correction from Rich of CruiseRO:

Hey Mike,

I just wanted to drop you a quick note after seeing hundreds of people coming to my watermaker site from your recent blog post (holy smokes… thanks for that by the way). I noticed something on the blog post that I wanted to mention to keep confusion from getting out there. 

The SM40 water maker wasn’t made to run from the Honda 2000 generator, the SM20 and SM30 were the two that were.  Now this doesn’t mean it won’t, but the 1.5Hp motor used by the SM40 uses 13A and the steady state Honda 2000 rated output is 13.3Amps.  So it CAN do it but it’s not something we encourage or promote.  Folks wanting to use the Honda 2000 should plan on using the SM20 or SM30. 


  1. Hi Mike,

    I’ve been thinking about watermakers for about 2 years now and have wondered about some things ever since I read some of your articles about the power draw and (maybe I remember incorrectly) noise that they generate.

    Inspired by the reverse-osmosis under-sink water filter in my house, I wondered why water-makers aren’t designed to use a pressure canister. The design for the system would be similar to the design of existing systems with one exception: Instead of running the water-maker drive pump the entire time you are making water, you would run the drive pump for long enough to fill the pressure canister with salt water. Air pressure in the pressure canister would then push water through the reverse-osmosis membranes to generate water.

    I can see some potential benefits do doing it this way:
    1. The water pump could be a less costly design than the continuous high-pressure pumps that seem to be required on current water-maker systems.
    2. I could probably design a water-maker pump that could be turned by hand if I had an electrical failure. I might spend a fair amount of effort pumping up the water system pressure with “fresh” seawater, but at least I’d get desalinated water out the other end.

    There are some possible complications with this idea:
    1. Salt water is way more corrosive than tap water.
    2. The pressure canisters I can buy at Home Depot are heavy.
    3. The pressure canisters I can buy at Home Depot are designed to work with typical city water pressures, and desalination water-makers may require more pressure.

    It seems like all of these complications can be addressed, but I haven’t seen any sign of anyone attempting to address them. The pressure canisters at Home Depot are mostly lined steel, but I imagine one could be constructed out of aluminum or carbon fiber. There are 100psi-rated air compressor tanks available in lots of places. I could imagine a completely air-driven design that uses pressure to push water through the water-maker and then if I release the pressure and allow the system to return to atmospheric pressure, it would draw water into the pressure tank.

    Why am I posting this on your blog? I’m just wondering if you’ve seen anything like this in your research or on any of the boats you’ve visited, or if you are aware of reasons why this wouldn’t work.


    • Hi Dave

      I am not an engineer (nor do I play one on TV) so can only speculate that what you’re describing can’t be done. In order to remove salt the water must be forced through the membrane at a fairly high pressure. Perhaps someone with more technical knowledge will comment.

  2. We’re kicking around the idea of getting a watermaker. I don’t know what we’ll ultimately decide, but I like your logic. If you’re already using the Honda Generator (which we plan on buying) why not produce more?

    Thanks for the info!

  3. Hi Mike,
    I can vouch for good service from your man. After reading your earlier blog about this watermaker, I emailed him and his response was almost immediate.
    Our problem is weight so something like ZTC’s watermaker would be more ideal for us and the other problem is bucks… with the South African Rand being so low to the dollar we looking at over R40K for one so we will have to build up the kitty or hope the bottom falls out of the dollar 🙂
    I do like the idea of the generator and was wondering what the preferred voltage is in marinas you have been to, in SA 220v is standard? We still in the throws of finishing our cat so haven’t set sail yet.

    Good luck with preparations for the Leopard.

    • The funny thing is, when I first emailed him I didn’t get a response. After a couple of weeks, I emailed him again. It turned out that our initial message ended up in his spam box and he missed it. Since that initial glitch, he has always responded within the hour to our inquiries.

      As for your power questions, most marinas in the Caribbean offer 220V/50HZ and 120V/60HZ. In our favorite Grenada marina, Port Louis, they have many more 220 docks than they do 120 ones.

  4. Mike,
    I bought a Technautics Cool Blue refrig system this year and have had outstanding customer service!!! Technautics is now owned and run by the same people at Cruise RO.


  5. … and then there are the hair dryers – your next problem after the Hollywood showers are done.

    And to Dave W:
    Those pressure tanks you see at Home Depot are rated for use with domestic water pressures – probably 100 psi max. For desalination you need much MUCH higer presures – 800-1000 psi. Aside from the fact that the homeowner tanks are woefully inadequate from a pressure standpoint, they would be terribly dangerous even if they were rated at 1000+ psi. They work by having an internal air bladder, which is compressed as liquid is forced into the tank. Liquids are incompressible – if a system filled with high pressure liquid ruptures, it is no big deal. But gases *are* compressible – a rupture of a tank holding 1000 psi air would be like a bomb going off. So your bladder tank would have to be built like a SCUBA tank, and would come with all the certification and maintenance requirements that go along with it.

    Finally, tho the amount of work that the system does is pretty much dependent on the output flow rate and the starting salinity, a system that has a pump that runs continuously will need a smaller motor than one that is idle for periods and then must run at a higher rate to catch up.
    (yes, I am an engineer)

    s/v Eolian

  6. As resident sailblog lurker, I can vouch from a “I’ve read his stuff” standpoint. Rich and his family’s adventures are well documented on their s/v Third Day blog. I like his take on the cruising life. It’s life, not camping!

  7. Hi R & M, Hope all going well, we just returned, as you know, from the Bahamas aboard our Lagoon 380 and just before we left, we installed a 20 gall per hour Cruise RO watermaker and of all the equipment we installed, this worked the best and gave us the freedom to journey far and wide without having to seek water or sit in long line ups waiting to fill water containers (a most popular Georgetown pastime!!). Can recommend this product with no reservations.
    Best J & D

  8. Perhaps if your clients have to listen to the Honda and RO noise for an hour a day they will learn to conserve a bit, like you have.

    I am trying to decide whether to go with an RO system or stick with simplicity. I have two 130 gallon tanks so, for the two of us, that is a lot of water. Still hate the idea of queuing up for questionable water so we are at standstill for now waiting for a brilliant flash of light:).

    Thanks for your thought provoking post.

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