watermaker

A watermaker is a device that produces potable water from saline or brackish feedwater. In marine and offshore contexts, watermakers are used on boats, ships, and submarines, as well as in off-grid homes, disaster relief scenarios, and remote installations where access to fresh water is limited.

The most common technology is reverse osmosis, which uses a high-pressure pump to force water molecules through semipermeable membranes, leaving salts and other contaminants behind. Other approaches include thermal distillation methods (such as multi-effect distillation or vapor compression) and electro-dialysis, which can be used with brackish sources. The resulting product water is typically treated or disinfected and stored for use.

Key components of a watermaker include pretreatment filtration (sediment and carbon filters), a high-pressure pump, reverse osmosis membranes, energy recovery or pressure-boost devices, storage tanks, and a control system. Power sources vary and may include shore power, onboard generators, or renewable energy. Capacity ranges from small portable units to large installations on vessels, with production rates commonly specified in gallons per day or liters per day.

Maintenance involves regular pretreatment filter changes, membrane cleaning or replacement, system sanitization, and monitoring of water quality to ensure safety. Performance depends on feedwater quality, temperature, system design, and proper installation.

Watermakers enable autonomous freshwater production for crews, cabins, and remote operations, reducing dependence on resupply and enhancing resilience in maritime and off-grid contexts.