Water Makers are a great way to refill your tanks without needing to go to a pier. If you are anchored in a gorgeous secluded spot, you won’t have to raise anchor and head to the nearest fuel dock to get more water. Instead, you can just stay in paradise and fill your tanks!
Water makers work by hyper compressing sea water on one side of a filter. This high pressure also leads to a “high concentration” on one side of the filter. Water will always want to migrate from one area of low concentration to another area of higher concentration. This process is called osmosis. Water makers work by creating such a high pressure gradient that they actually reverse this normal osmotic process and cause the water to literally be squeezed out of the super salty solution and back across the filter to an area that is completely salt free. This is why water makers are also called Reverse Osmosis Machines.
As you can imagine, this process requires a lot of power to produce the pressure gradient, and this power is typically supplied in the form of electricity.
Electricity powers the pump that generates the intense pressure and literally squeezes the fresh water out of the super salty solution. The result is fresh water that goes into a water tank and brine (super salty water) that is dumped back into the sea.
Electric water makers can generate a few gallons per hour, but the cost of electricity increases just as fast as the gallons produced per hour. If you want more water, you are going to pay for it with more amps!
The alternative to electronic water makers are manual water makers, which rely on the power of leverage and good old arm strength! These units are typically considered “survival gear” or for emergency use. You would probably use one of these devices to fill a glass of drinking water instead of using it to top off your giant water tank.
While these units do not require the use of electricity, they will more than makeup for the power demands from your arms! These units can produce just as much water as an electric unit, independent of your electrical bank, but it could also double as your own personal exercise regimen.
Water makers are great, but they are best thought of as a way to top off your existing water tanks that are capable of sustaining you on your voyage and not as a source of endless water which negates the need for water tankage in your yacht.