Rainman portable watermaker – 12V DC – 34L
This 12V DC watermaker is designed for efficiency, simplicity, and low maintenance. Built around a durable triplex plunger pump, it offers lower flow rates and power consumption—ideal for boats with limited electrical systems. While technically portable, this unit is more commonly installed due to its compact power needs and shorter cord requirements.
Two components, one system
The Rainman watermaker includes a pressure supply unit (PSU) and a reverse osmosis (RO) unit. The PSU draws and filters seawater, then pressurises it for desalination. The RO unit extracts fresh water, producing roughly 20% clean water and discharging the rest as brine. This setup ensures a reliable source of potable water on board.
Flexible and future-ready
Not sure whether you want a fixed or portable setup Start with the portable watermaker. Use it off-the-shelf and install it later if needed. This flexibility lets you test different configurations before committing to a permanent install—especially useful on small or custom vessels.
After a couple of uses, setup takes just minutes:
- Position the PSU and RO units (can be left in a locker)
- Connect the high-pressure hose between the units
- Place the seawater intake and brine discharge hoses
- Power on and slowly increase pressure to 55 bar (800 psi)
- Collect fresh water and fill the tank
- Depressurise and stow when finished
Whether for bluewater cruising or weekend sailing, this marine desalination system brings dependable fresh water to your adventure.
| Output Expectations | 45 - 55 lph / 12 - 15 gph |
| Enclosure | Two part system, pressure supply unit (PSU) and reverse osmosis unit (RO) |
| Pressure Supply Unit (PSU) | Case of sturdy injection moulded polypropylene |
| RO Membranes | One 2.5" x 40" seawater membrane |
| Reverse Osmosis Unit (RO) | Case of injection moulded polyethylene, strengthened with fibreglass reinforced nylon |
| High Pressure Pump | General Pump / Rainman WMR triplex plunger pump |
| Operating Pressure | 55 bar (800 psi) in seawater |
| Pressure Relief Valve | Integrated General Pump 316SS |
| Prefilter | 5 micron |
| Lift Pump | Integrated Rainman bronze flexible impeller |
| Vertical Water Lift | 2 metres (6 ft) |
| Control Panel | N/A - Can convert to installed unit |
| Autoflush | N/A - Can convert to installed unit |
| Power Source | 24VDC |
| Power Use | 600 Watts |
| Current Draw | 24 Amps 24VDC |
| Motor Type | Permanent magnet TEFC DC |
| Plug Type | Anderson Style |
| Power Cord Length | 1.4 metres (4.5 ft) including battery connectors AWG 8 |
| Subjective Sound Level | Soft hum |
| Measured Sound Level (6 metres in open lot) | 58dB |
| HP Hose | 5 metre (16 ft) |
| Product Water Hose | LDPE food grade product water hose - 3 metre (10 ft) 10 metre (33 ft) extension (8mm OD) |
| Brine Waste Hose | 3 metre (10 ft) brine waste discharge (10mm OD) |
| Intake Hose | 5 metre (16 ft) fitted with one way valve to remain primed (1/2" ID), with detachable strainer |
| Impeller | Included in pump (replacement Rainman MI813 or Jabsco Profile D 22405-0001-P) |
| 5 Micron Prefilter | 1 in housing 4 spares - 10" x 2.5" pleated poly |
| 20 Micron Prefilter | N/A |
| Activated Carbon Filter | N/A |
| Pickle Solution | 1 kg (2.2 lb) sodium metabisulfate powder |
| Valve / Gauge Control | Integrated in RO unit |
| Low Pressure Gauge | N/A |
| Salinity Sensor | Optional hand held HM Digital COM-80 |
| Product Water Flow Meter | Pop-up acrylic plastic analogue flow metre - 160lph/42gph |
| Plumbing Installation Kit | Optional |
| RO Unit Dimensions | 1,180 x 250 x 130mm (23.6 x 9.8 x 5.1") |
| Pressure Supply Unit (Modular) Dimensions | 600 x 375 x 270mm (23.6 x 14.8 x 10.6") |
| Control Panel | N/A - Can convert to installed unit |