Watermakers for yachts
A cruising yacht usually has more solar than generator, limited machinery space, and an owner who would rather not run the engine to make water. That combination pushes hard towards efficiency, and it is the case the whole watt-hours-per-litre argument was built for.
The power reality. Most cruising yachts are DC boats. If your engine only runs to lift the anchor, every litre has to come out of your solar surplus, and a five-fold difference in energy per litre stops being academic.
What matters on yachts
Your surplus, not your array
A 400 W panel gives roughly 1,600 Wh on a clear Queensland day, and the fridge takes a large share of that before anything else. What is left is your water budget.
Machinery space is the real constraint
Modular systems split the pump, filters and membranes so they can be distributed around the small voids a yacht actually has. Framed systems need one space big enough for the lot.
Cable runs are longer than you think
On a DC system, voltage drop between the bank and a pump in the lazarette is a common cause of a system that underperforms from day one. Size the cable for the run, not the load alone.
Heeling and the intake
An intake that works at anchor can draw air on a long port tack. Placement matters more on a sailing yacht than on anything else.
Shortlist for yachts
The 8 best matches of 20 that suit yachts, ordered by energy per litre. Run time and energy below are for 75 litres a day.
| System | Power | Output L/hr | Draw W | Wh per litre | Price |
|---|---|---|---|---|---|
| Zen 30 Schenker | 12/24V DC | 30 | 110 | 3.7 | $6,300 |
| Zen 100 Schenker | 12/24/48V DC or AC | 100 | 400 | 4.0 | $9,600 |
| Ventura 150 Deluxe Spectra | 12/24V DC | 24 | 108 | 4.5 | $6,000 |
| Ventura 150 Connect Spectra | 12/24V DC | 24 | 108 | 4.5 | $7,400 |
| Newport 400C Spectra | 12/24/48V DC | 64 | 288 | 4.5 | $14,500 |
| Zen 50 Schenker | 12/24V DC | 50 | 240 | 4.8 | $7,800 |
| D100 DUO Dessalatorreported | 12/24V DC | 100 | 700 | 7.0 | on request |
| D60 Freedom Dessalatorreported | 12/24V DC | 60 | 550 | 9.2 | on request |
Common questions
- What is the best watermaker for a cruising yacht?
- For a solar-powered yacht without a generator, an energy-recovery DC system: it makes 100 litres for a few hundred watt-hours, where a conventional pump on the same output can need five times that. If your engine or genset runs daily anyway, a conventional system gives far more output per dollar.
- Can a yacht watermaker run off solar?
- Yes, with the right system. An energy-recovery unit at about 3.7 Wh/L makes 100 litres for roughly 370 Wh, which one 400 W panel covers on a clear day. A conventional unit at 19.7 Wh/L needs nearly 2,000 Wh for the same water, which is not realistic on solar alone.
- How many litres per hour does a yacht need?
- Enough to make your daily total in one to two hours. For a couple that is often 20 to 30 L/hr; for a family of four, 50 to 100. More output shortens the run but usually raises the draw on a conventional pump, so check Wh per litre rather than assuming bigger is better.
Guides that go deeper
Not quite your boat?
How the shortlist is built. 75 litres a day is 3 aboard at 25 litres each — a planning figure for this kind of boat, not a measurement of yours. The list is filtered to systems whose power source suits yachts and ordered by energy per litre. Every figure is the manufacturer’s rated output and draw; Wh per litre is one divided by the other. Methodology.