a fresh approach to desalination

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RAINMAN Desalination

Demand for fresh water on pleasure craft has increased dramatically in recent decades.  Many of us now expect daily fresh-water showers, pressurised plumbing, and unlimited drinking and washing water.  Obtaining water on shore from jetties and marinas is becoming difficult, expensive and the quality is an unknown. 

Having your own desalination system provides you with  independence and flexibility.  Until now, the only option has been a complex system built into your boat.  The high cost, complexity, and maintenance requirements of such systems have been daunting. 

Rainman Desalination, have developed the world's first simple, low maintenance, and inexpensive water maker that doesn't need to be installed in to your boat.

As the exclusive Rainman Distributor for Menorca, we can supply and install and of the Rainman range. 

Desalination Theory

Desalination sounds complex, but it is really quite simple in practice.

The Rainman desalinator works by 'reverse osmosis', where high pressure is used to force water through a membrane, leaving pure water on one side, and salty water on the other. It's a bit like forcing water through a filter, except with reverse osmosis the pure water is forced through the membrane on a molecular level.

Sea water reverse osmosis takes a lot of pressure- about 800 PSI or 55 Bar. That's about the pressure you'd find half a kilometre beneath the sea.

In the Rainman desalinator, a Honda engine or electric motor drives a Jabsco impeller pump and a General Pump high-pressure plunger pump.  If the setup reminds you of a high-powered pressure washer, it's because it is similar.  Honda engines and General Pump Piston Pumps are the workhorses of the commercial pressure washing industry.

The impeller pump lifts the seawater, and the high pressure pump raises the pressure to around 800 PSI.

The high-pressure seawater is fed into a fiberglass pressure vessel that contains a Dow Filmtec reverse osmosis membrane.

The water flows past the outside of the membrane, which resembles a hollow plastic tube.  In fact, the membrane is layer upon layer of thin films of plastic, which allow fresh water to permeate through to the inside of the tube.

Only a fraction of the high-pressure seawater is converted to pure drinking water.  About 85 percent simply washes by the membrane and is flushed out the other end.  It might seem wasteful, but the constant flowing of water past the membrane cleans it, preventing the membrane from ever clogging up.

The system has been designed to be as simple as possible for maximum reliability and easy maintenance.


How Desalination Works ?


  • Optional installation helps both cost effectiveness and ease of future maintenance
  • No electronics to fail or corrode
  • No generator required for the 'stand-alone' petrol version means you don't need to run the main engine or generator  to operate the system

Installed or Portable? Its Your Choice

Although the Rainman watermaker was originally designed as a portable system not requiring installation, many of our customers choose to partially or fully install the system in their boat.  The variations can range widely, including installation of both the pressure supply unit and reverse osmosis case, to installing one or the other of the units.



Which Rainman System is Best For You?

STEP 1 - Choose the Pressure Supply Unit

AC Electric

230V/50Hz or 115V/60Hz 1300W
Minimum generator required: 2kW​

DC Electric

12VDC/ 400W

​​Petrol (stand-alone version)

Honda 50cc 4-Stroke petrol motor
No External Energy Source Required

STEP 2 - Choose Reverse Osmosis Unit

High Output

2 x 40" RO Membranes (100 - 140 litres per hour)


2 x 21" RO Membranes (50 - 70 litres per hour)


Single 40" RO Membrane (50 - 70 litres per hour)

Rainman PRICES


Recommended € Price

Pressure Supply Units (PSU)

Electric (230V/50Hz)€ 3,600
Electric (115V/60Hz)€ 3,600
Electric (12VDC)€ 3,850
Petrol / Gasoline - Honda 50cc 4 stroke   € 4,550

Reverse Osmosis (RO) Cases

High Output Case - 100-140lph (23-32gph)€ 2,250
Compact Case - 50-70lph (12-16gph)€ 2,000
Economy Unit - 50-70lph (12-16gph)€ 1200
High Output Naked (no case) - 100-140lph (23-32gph) € 2,100
Compact Naked (no case) - 50-70lph (12-16gph)€ 1,950

Accessories and Spares

Pressure Gun Attachment€ 180
Pre-Filter Cartridge (5 micron)€     8
HM Digital COM80 Hydrotester€   40
Jabsco Impeller Replacement€   32
Brackish Water Flow Gauge€ 340
Pickle Solution Mix - 1kg (2.2lb)€   16
Canvas Cover For Pressure Supply Unit€   70
40" RO Membrane (Filmtec)€ 280
21" RO Membrane (Filmtec)€ 265
5 metre high pressure hose€   68

Please note: Prices include IVA TAX, but Shipping is excluded.

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