Spectra, Schenker, or Rainman — the watermaker question I keep circling
Three watermakers, three failure modes, and I still don't know which one I want at 200 miles offshore with four kids aboard.
Every time I sit with the systems list for the 50-foot cat we're researching, the watermaker line goes quiet. I'm not closer to a decision than I was three months ago, and I think that's worth writing down before I pretend I am.
Three options keep ending up on the worksheet. The Spectra Catalina 340 — 14 gallons per hour, 9 amps at 12 volts, runs straight off the house bank while we're sailing. List install is somewhere around $13,500 once you factor in the bracketry, the boost pump, and the second strainer most installers want. The Schenker Modular 60 — 16 GPH on AC, around $10,500 installed, runs off the inverter or shore power. And the Rainman Naked AC — 37 GPH out of a 110V box that costs about $5,500 and that I can lift out of the locker if something fails.
The advisor brain keeps wanting to optimize for cost per gallon over five years and call it solved. That's not the right question. The right question is what kind of failure I want to live with at 200 miles offshore with four kids on board.
Spectra's pitch is the seductive one. With 3 kW of solar across the bimini and a 600 Ah lithium house bank — call that a real-world 480 Ah usable — making water becomes a byproduct of sun. Set the unit to run an hour after lunch, net 14 gallons, the bank barely notices. On the right boat with the right solar, the math is genuinely good. On the wrong day with overcast skies and a fridge compressor that won't quit, that “free” gallon costs you 1.5% of usable bank.
The thing that pulls me back from Spectra is parts. A Clark pump rebuild is not a passage repair. The membranes are proprietary. If we're in the Marquesas and something goes, I'm not the one fixing it — I'm waiting on a freight forwarder out of Tahiti for two weeks while the kids drink rationed water and Sarah and I rehearse the conversation about why I didn't just buy the simpler box.
Rainman is the opposite trade. The unit is dumb, lifts in and out, runs on standard pumps and a Honda-style brushed AC motor. Anything that breaks, I can probably source from a chandler in any port that has Yamaha outboards. The cost is that Rainman wants to draw 1,200 watts of AC, which on our cat means a 3 kW inverter running hard or a generator we'd otherwise not need. We'd been planning the boat as a generator-free build. Rainman quietly puts the generator question back on the worksheet.
Schenker sits in between and keeps not winning the argument. Not as efficient as the Spectra, not as repairable as the Rainman, not as cheap as either. The Italians make a good unit, but “good enough at everything” keeps losing on a long passage list.
Where I'm landing this week — not committing — is that the Rainman plus the existing 3 kW inverter is probably the right answer, and the Spectra is the right answer if I commit to a generator-free build with serious redundancy in the membranes and a spare Clark pump in the bilge. The Schenker is the answer for a different boat than the one I'm building.
If you've crossed an ocean with any of the three, I want to hear what actually broke and how far from help you were when it did. That's the data point that's missing from every brochure.
More notes like this — and the worksheet itself — at the boat worksheet.
