Equipment | Watermaker

Watermaker

Watermakers are becoming more and more popular on board cruising yachts as the price and complexity falls. We have a 12 volt electrical motorised reverse-osmosis system called a PUR 80, designed by Recovery Engineering (based on work to develop an energy-efficient hand-operated desalination unit that could be operated by shipwrecked sailors). The PUR-80 produces about 12 litres of fresh water an hour, consuming about 9 amps at 12 volts. We tend to run it about 3 hours a day, usually when the generator is running.

The PU 80 consists of a pre-filter (that takes out the large particles from the seawater intake) a high-pressure pump (driven by a 12 volt motor) and a very expensive membrane that separates the salt from the seawater. The freshwater outflow is directed to the tanks, the (slightly salt-enriched) waste seawater is routed overboard.

The expensive membrane (that does the real magic work of separating salt from seawater) is housed in a long cylindrical casing under the saloon cabin sole.

The high-pressure pump (driven by a 12 volt electric motor seen on the right) is also under the floor, nearby.