115V Rainman Watermaker System – High Output – 26 to 37GPH

(33 customer reviews)


IN STOCK – Ships Within 24 Hours

USA Delivery – 3-7 Business Days From Order

The Rainman high output watermaker system is capable of producing between 26-37 Gallons of drinking water per hour from sea, brackish and freshwater sources.


This is the most popular Rainman Watermaker System!

The Rainman Watermaker 115V desalination system with high output membrane is ideal for vessels and applications that have access to AC power – such as a Honda EU2000 or good quality 2KVa inverter.

No installation necessary – easy 10 minute setup – from unboxing to water production!



These portable desalination systems are ideal for applications with ac power, such as a Honda 2000 watt generators and are the most popular rainman watermaker on the market. Simply unbox, plug in and make water – set up is less that 10 minutes and your capability extends for up to 37 gallons per hour. Eliminate those water worries with a Rainman Watermaker.

  • Sturdy injection moulded polypropylene shell.
  • Totally enclosed fan cooled (TEFC) induction motor.
  • Draws 1250 watts in steady state operation.
  • Designed to run with minimum of a Honda 2kW generator or a quality 2kVA inverter.
  • Pre-filter and housing externally mounted for ease of service.
  • Jabsco impeller pump to lift water and provide positive pressure to the high pressure pump.
  • General Pump WMR series 316 stainless steel high pressure pump, the workhorse of the RO industry.
  • General Pump relief valve to prevent overpressurisation and allow for pressure washing.
  • Sturdy 15ft draw hose fitted with one way valve so it remains primed, with detachable strainer.
  • Five 5 micron pleated paper pre-filter cartridges included.
  • 2.2 lb bag pickling solution powder included.
  • Dimensions: Length 23.5″, Width 10.5″, Height 13.5″
  • Weight: 54lb

The high output membrane is the flagship model - designed specifically for the Electric high portable desalination power systems. With the High Output Case, you can expect to produce between 26 - 37 GPH. This is our most popular and highest output option.

  • Two 40″ Dow Filmtec RO membranes will produce 26 to 37 gph, depending on source water temperature and salinity.
  • If desired, it the entire case can be permanently mounted, or internal system can be removed and installed with included rubber mounts.
  • All salt water plumbing is 316 stainless steel.
  • Quality fluid filled pressure gauge.
  • Integrated Flow Gauge for use in brackish/fresh water
  • 316 stainless steel pressure valve for long life.
  • Rugged polyethylene case.
  • 16 ft input hose with quick fit connector for connection to pressure supply unit, won’t mark your deck.
  • 10 ft food grade polyurethane fresh water delivery hose.
  • 33 ft food grade polyurethane extension hose for reaching your forward water tank.
  • 10 ft brine waste hose.
  • Dimensions: Length 46.5″, Width 5.75″, Height 9.75″.
  • Weight: 52lb.

All systems come complete with a full supply package of filters and pickling solution mix, tools and manuals. Ready to operate out of the box.

Portable systems also complete with a moulded strap down system for added storage options.

Additional information

Weight 120 lbs
Dimensions 26 × 11 × 15 in

33 reviews for 115V Rainman Watermaker System – High Output – 26 to 37GPH

  1. John Frederick

    Hi Chris, Just wanted to update you on my Rainman Water Maker unit (that I bought last October). I finally got away from the dock and made some water yesterday in Galveston Bay. The water was about 60 degrees and somewhat brackish. The unit worked wonderfully. To measure output I filled a 5 gallon bucket in 7 minutes. Fantastic. And the water tested out at 25 ppm solids. I can’t imagine any better than that. I tested the water from my Sea Gull filter…225 ppm. So the Rainman is making nearly pure water. I am a very satisfied customer so far. Thanks! John

  2. Travis Wizniuk

    I want to comment on Seatask (http://www.seataskgroup.com/rainman), the dealer I ordered it from. They are truly one of the best companies I have dealt with, EVER. Their pre, during and follow up service is absolutely fantastic. In the above post, I commented that I would be on my own once I purchased. I no longer feel that is true. Seatask has e-mailed me every month to ensure I’m still happy with the product and that I’m not having any issues. I’m absolutely sure that if I had issues and needed parts, they would go out of their way to ensure I got them anywhere! An honest to goodness first class company….

  3. Andrew Danielson

    It seems to be bullet-proof. I haven’t had any issues that changing the pre-filter didn’t fix. On the other hand, I have a couple of cruising friends who spent much more on installed systems, and they still haven’t been able to get them to work. One is in Bimini, and he’s afraid that he’ll have to return to the US with his boat to get it fixed. I pointed out to him that with a Rainman, he could have just shipped it back while he continued to cruise! I’ve checked in with your booths at the Annapolis and Miami boat shows. Great crew you’ve got!

  4. Rhory McNamara

    Hi Chris , Just a quick note to say I am using the rainman water maker for second time on trip in grenadines and it is amazing. Have been alongside some bigger sport fisherman and I am making more water than them an hour compared to their permanent systems and they are astounded at how simple and inexpensive the rainman is compared to their units
    Worth every penny – off to have another lengthy shower with no regret or remorse!.
    All the best and thanks again.

  5. Matt and Lucy

    We purchased the Rainman from SeaTask in Ft. Lauderdale. Chris has been wonderful showing us how to use the unit and answering follow-up questions. We have no affiliation, just happy customers!

  6. Robert Sapp

    Now we have it on good authority that dying of thirst is very stressful. We personally wouldn’t know, but it sounds reasonable, so we’ll go with that. Not being able to take a shower or properly bathe for days upon days? Stressful. Having to plan your travels and itinerary around sources of potable water because the tank level is always bumping empty? Stress city. What’s the common factor here? Water, and the access to and availability of same. So we felt that one piece of equipment we definitely wanted onboard was a watermaker….

  7. Ricardo

    Hi Chris, I did enjoy a full week of sailing with my family just recently. We were 6 adults and 4 grandchildren , sailing the Spanish Virgin Island in my 42′ catamaran. We didn’t have any problems with our fresh water supply thanks to the Rainman system. It worked great, as I expected. I highly recommend this device. Thanks for your professionalism, it always a honor to deal with a gentleman like yourself

  8. Captain Bill – Klickitat

    After an obsessive month of research we decided to go with a Rainman unit for our sailboat in Panama. Chris at Seatask did an extraordinary job of answering lots of questions, and more importantly made the whole purchase and delivery process happen very quickly. We got the unit in plenty of time to pack it up like a suitcase and carry it with us on an international flight in order to avoid delivery charges. All was flawless. Product is exceeding expectations. Very easy to install/stow in a large lazarette, but we still have the flexibility of moving it in order to access other mechanical items, or to service the unit. Great product, really great service..

  9. David

    Chris, Thanks again! Like Christmas morning, I couldn’t wait to play with my new toys. Pressure washer is awesome and gets the grime off the deck. We’re filling our tanks with water now. Getting about 177ppm and my daughter, who is a water snob, says the water tastes very refreshing! Thanks again!.

  10. Nick J

    Thank you, everything is well and the system works perfect for us. I would not want to have any other systems on board, so easy to use and maintain

  11. Gary

    Hello Chris. We love our Rainman watermaker and rave about it to everyone we meet while cruising the Bahamas. We have probably made over 1000 gallons since arriving here in November.
    My favorite feature is the high output which I don’t think we would get with a traditional watermaker. I can fill our two 75 gallon tanks in about 5 hours. Usually less as both tanks are rarely completely empty. This is a huge adavantage over the 8 to 12 gallons per hour others tell me they get with their traditional units.
    The Rainman was the right solution for us. An installed unit would have cost more than double the price and the output would have been much less.

  12. David – SailQuest

    We ordered ours from Sea Task Group, in Florida. But you have to keep in mind, we don’t have a home address for shipping. So we arranged for them to ship it to a marina in the Bahamas. That means we had to arrive at the marina, and it had to arrive at the marina, at the same time (give or take a day). Our salesman did an amazing job, getting the unit ready for shipping, and then personally driving it to the airport to make sure it would be on tomorrow’s flight. Sure enough, the next day it was at the airport in Nassau. We rented a car and drove to the airport, got it cleared through customs, and it was ours! What amazing service we received.

  13. Mike K

    Chris, Just finished our first run with the Rainman watermaker. Ran it off of our Honda 2000i generator. It worked great! We were getting 36.5 gallons/hour out of it. Very happy! Cheers.

  14. Louis B

    Chris, Wanted to let you knowhow pleased we are with the watermaker. Really impressed with the performance of the unit and the simplicity of its ​design. Thank you very much

  15. Virgil Allmond

    Chris, Love our Rainman!
    Making Water in the Bahamas!

  16. Mike Baker

    Chris -The Rainman watermaker was Great, so easy to set up and use. Took me about 4 hours to fill my water tank, 120ltrs. It makes a big difference when cruising not to have to plan where to take on water, or wasting all that time taking 20ltr containers to the shore to fill up. I had some friends staying at various time and did not have to worry about water usage. I even rinsed my boat down a few times after it for sprayed with salt water. I fitted a wash down pump and felt so go washing down at anchor

  17. Julian O

    Spent two months in the Bahamas this spring and used the Rainman every five days. No issues easy to use and provides a great deal of confidence. My wife could do wash on board when ever she wanted without any concern for our supply of water

  18. Keith Marler

    Super happy with my rainman system. Easy and reliable along with great tasting water. So easy to set up and run.

  19. SV Kinetic

    Rainman is making water – hallelujah! Topside tests and tweaking onboard electrics, tanks the filling now. Rainman will be installed in the “garage” for future operations.

  20. SV Alizarin

    We love the Rainman. It does fantastic water…great taste! We are making water about every 5 days/30 gal/hr (except now that I am home for 3 weeks we won’t be) it’s really quick to set up. It is somewhat noisy while we run the generator with it but I just go for a paddleboard or put the music on with headphones. Recommend highly!!

  21. Travis

    Yes the Rainman and Honda are working fantastic. We opted to install the Rainman and use our existing thru-hull and sea strainer. The installation was simple and we have made hundreds of gallons of water since then.
    So far we are ecstatic with the performance and very happy with our purchase decision. We are able to supply enough water for our family of five (including laundry) by running the watermaker just 3 hours a week (sometimes more if we swim alot, no one likes to be salty).
    We really appreciate the excellent product and fantastic service.

  22. Doug Ousley

    I am not in the habit of writing reviews of marine products. In the case of the Rainman watermaker I am making an exception. My wife and I are true liveaboard sailors. We don’t just live on our boat for six to eight months at a time like an extended camping trip. It is our only home 24\7, 365 days a year. We have owned our forty-one-year-old 37’ Endeavour for 18 years and have lived aboard full time sailing the Gulf of Mexico, Bahamas and the Caribbean since 2011. We are currently in Guatemala. We put all systems to the true test of sustainability by using them daily, year in and year out.
    We purchased the Rainman in 2016. The reason I did not write something until now is that I believe it takes a couple of years to have a good enough data set and maintenance record to base an accurate assessment on.
    We purchased the 110V Rainman for use with our existing Honda 2000 Generator. We also purchased the High Output Case, HM Digital COM80 Hydrotester, and Brackish Water Flow Gauge.
    I keep data for performance and maintenance purposes on each use. My findings are as follows. The 32 gals per hour is our average. It can reach 37 gals but this is why the I would recommend the purchase of the Brackish water flow gauge. Even low salinity salt water can increase flow to necessitate monitoring the gauge to avoid stressing the membranes. In other words, the Rainman works better than advertised in our experience. The maintenance schedule provided in the manual is straight forward and simple to follow.
    In short, the Rainman will change the way you liveon your vessel, giving an economical an easy way to have as much fresh water as you would like​

  23. Geoff Wallace

    The Rainman performs as advertised. I’ve enjoyed its 38 gallons/hour production of fresh water during my first year of ownership this past summer, and have mastered its setup and storage process. Pickling in preparation for more than 4 or 5 days (depending on the ambient temperature) of non-use is a breeze. The portable pump and membrane units are heavier than I expected, however their combined weight is considerably less than the water maker that was previously installed in the boat. Would certainly recommend adding the flow meter to the system…I sail in some brackish water and the flow meter is easy to understand and helps to control flow and protect the membranes in that case. I have only praise for the Rainman. Anyone with questions is welcome to contact me at email: [email protected].
    Stu Hochron
    S/V Blewberry Pancakes

  24. Jeff Liebel

    Took the unit with us to Florida where we keep our boat and sailed to Bahamas for the winter. Wow what a cool piece of machinery. In the very clear waters of The Bahamas we were making 18 to 20 gal. of fresh water per hour. That was measured and timed several times. This is more than it was rated for so I was very pleased to say the least. I would top off the gas tank and get about 1 1/2 hours of run time on one tank. and because we used it about every three days only back flushed the unit with about 2 gal. of fresh water each time which should be good for at least a week. And the unit is portable, so cool. Very pleased with the product and the great service from Chris.

  25. Motts Mueller

    My experience with Seatask and the rainman watermakers has been excellent. Chrstopher Burton was extremely helpful and responsive in every step of the purchase/deliver/setup. He helped me figure out what I needed and shipped it quickly.
    The unit itself is great. Easy to setup, easy to use and exactly what we needed (a reliable, portable watermaker to extend our cruising range and reduce reliance on shoreside solutions in the Caribbean).

    Will likely buy another one next year for our fleet.
    I highly recommend this company and product

  26. Harry Munro

    Chris and his team did a great job helping us with getting our unit through French Customs in La Rochelle. We used our Rainman watermaker on a daily basis as we spent forty days total (thirty at sea) crossing the Atlantic from La Rochelle to Tortola BVI. We had six on board and so each day we’d top up our tank averaging 150 litres a day which took the rainman about 11/4 hours to make from beginning to end. The system is simplicity itself and after the first couple of times became just a routine of life on board. Our skipper who has fought and lost with many types of watermaker was most impressed.

  27. Richard Brown

    Christopher Burton responded to my email questions quickly, obviously he knows his stuff. I started looking seriously at a water maker about one year ago. Having a 4kw generator made the electric high output unit the best choice for us. The portable aspect was the clincher, not having to install parts and pieces was the second most important issue. Taking the water maker off the boat for the several months when we don’t cruise, and storing it in a closet at home, is huge. It was extremely easy to lift the unit out of the lazarette, set it on the deck and drop the hoses overboard. The review from The Boat Galley was helpful. There is nothing as nice as not having to constantly remind people shut off the water.

  28. Claude Dormoy

    Practical and easy to use – Best customer service I have ever received

  29. Bob Huether

    Great support for an outstanding product. This is the best system ever. Easy to operate and very energy efficient when coupled with the Honda E2000 generator. I’m recommending this to my friends in the cruising community

  30. David Fulton

    All Seatask support has been excellent and we know we the right decision going with the Rainman system, It has worked as advertised. We are very happy with the system

  31. Fraser Speir

    Wow. Easy to deal with very helpful.

  32. Chris

    Love it. Very compacted. Chris has been a hands on person keeping in touch. I have provided water for others in the Bahamas and this desalinator seems to sell itself.

  33. Paul W

    I have been cruising the Bahamas with my Rainman Watermaker for a bit over a month so far. I have a good sized generator so the high output 120v unit was my choice. I don’t need a Watermaker when near my home cruising ground so a portable, removable unit made a sensible choice. I leave the pump unit in a rear locker, haven’t moved it since I dropped it in there. I did run a 120 v outlet to this locker to keep things clean and easy. That was a quick install. I do have to carry the filter unit up on deck when I use the Watermaker but that seems to be a lot less work than doing a real permanent installation. I seem to run the Watermaker twice a week for a few hours to meet my needs, but the generator needs exercise anyway and I use it to charge batteries at the same time. This has been trouble free so far and it’s really nice to feel self sufficient while cruising. Chris at Seatask has been great for pre and post purchase questions. I like being able to rinse the boat with fresh water and not have to limit my guest use of water. Altogether this has been a great addition to my boat.

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