The devices can be expensive to acquire and maintain, but are quite valuable because they reduce the need for large water tanks for a long passage.
Depending on the design, watermakers can be powered by electricity from the battery bank, an engine, an AC generator or hand operated.
[2][citation needed] Popular brands of yacht watermakers typically make from 2 to 150 litres per hour of operation (0.53 to 41 gallons) depending on the model.
As a guideline, assuming a 12V DC system, the energy recovery incorporated in those watermakers have the effect of reducing the electric current used from perhaps typically 20A to about 8A.
All watermakers designed for small boats and yachts rely on essentially the same technology, exploiting the principle of "reverse osmosis": a high pressure pump forcing seawater through a membrane that allows water but not salt to pass.