Watermaker

[Kings Gambit]

I did not get one on Black Friday, but having one installed within the next few months is in the forecast. I’ve noted that even small electric units might produce a couple of hundred gallons per day (assuming available power). I have only about 75 gal tankage for water; personal on board consumption (i.e., drinking) is approximately one gallon per day/person. Is there a need for more water production on a 38 ft sailboat, assuming two crew? It seems there could be only widely-spaced intermittent use of even the smallest units. Not good for watermaker units I’ve heard. Are there recommendations, insights, opinions? Might it be best to “gallon-up” for daily consumption each morning? Keep it in daily use?

KG

 

[dlochner]

I've also heard that water makers should not be left idle for long periods of time. Common practice is to run them every few days to top off the tank. With a small crew bigger may not be better.

 

[Kings Gambit]

P

I've also heard that water makers should not be left idle for long periods of time. Common practice is to run them every few days to top off the tank. With a small crew bigger may not be better.

Smaller to smallest might prove the most practical for several reasons, e.g., space and power demand, etc. Just don’t know much about them in use at present.

 

[Kings Gambit]

Running the Spectra Ventura 150 MPC @ 6 gal/hr for an hour every other day (9 amp-hr use every two days) should keep us up; could run it longer if needed at the end of each week, etc.

 

[dlochner]

I had looked at and considered a couple of portable ones and thought they would meet the needs of our 2 person boat. However, since we live in freshwater and would only use it for a couple of extended cruises in the saltwater, it was just cost prohibitive.

 

[Kings Gambit]

Admiral wishes several gallons of purified drinking water aboard whenever we’re away from home on the boat, esp. if away for long. We can stow and carry it, but altogether it takes about as much space as the small watermaker likely would. Then we sometimes have to buy it, and then lug it, etc., depending. (We can purify at home.) But, it’s another planning step, articulation, in preparation. With another couple aboard, double it of course. Financially speaking, probably not a good “return” unless traveling or at anchor for weeks on end. If moving onto a mooring for some period, which could happen , then a very nice feature.

 

[dlochner]

Running the Spectra Ventura 150 MPC @ 6 gal/hr for an hour every other day (9 amp-hr use every two days) should keep us up; could run longer if needed at the end of each week, etc.

That's what we were looking at. The ah draw can be minimized if the water maker is run while the diesel is running, when anchoring or leaving anchor or on windless days.

 

[Kings Gambit]

That's what we were looking at. The ah draw can be minimized if the water maker is run while the diesel is running, when anchoring or leaving anchor or on windless days.

Yeah! Water making could included with the daily/bi-daily battery charging routine.

 

[dlochner]

Yeah! Water making could included with the daily/bi-daily battery charging routine.

A good quality 150w solar panel would provide enough power to run the watermaker every sunny day for an hour and then some.

 

[Don S/V ILLusion]

We have a Spectra 400 which exceeds our need usually but with guests or grandkids onboard, it turned out to be barely adequate at times so my suggestion is to never underestimate demand.

Maintenance amounts to flushing or changing filters and seals periodically but no more so than any engine maintenance chore. Parts are widely available. There is no need to pickle the unit unless you anticipate prolonged idle time but I do it between trips just because I’m anal.

if you are concerned with power requirements, there are units which can be belt driven off the engine.

 

[Kings Gambit]

A good quality 150w solar panel would provide enough power to run the watermaker every sunny day for an hour and then some.

Presently, I’m routinely carrying an 80-watt but I have two of them that can be joined to get 160 watt, nominally. Together, in a couple of hr of full sun, could easily put out 9 amp-hr with some to spare.

 

[Kings Gambit]

Maintenance amounts to flushing or changing filters and seals periodically but no more so than any engine maintenance chore. Parts are widely available. There is no need to pickle the unit unless you anticipate prolonged idle time but I do it between trips just because I’m anal.

I’d do that as well (pickle), along with all the other things required to put the boat down until the next trip. Longer intervals between ‘em it seems like now.

 

[Kings Gambit]

I suppose these units require a dedicated seawater intake thru-hull, and then one for outflow of brine as well? Two more holes through the bottom of the boat?

 

[dlochner]

The brine out flow could flow in to a sink drain or through a thru hull above the waterline. You might be able to T into an existing line for the intake, maybe the head intake.

 

[Kings Gambit]

The brine out flow could flow in to a sink drain or through a thru hull above the waterline. You might be able to T into an existing line for the intake, maybe the head intake.

I was thinking along those lines.

 

[dlochner]

I was thinking along those lines.

GMTA

 

[Caboteur]

I carried 300 liters (±75 US gals) and did 4 Atlantic crossings with a crew of three or four aboard! That's three weeks each crossing without touching land! Didn't have a watermaker and didn't run out of water. For safety reasons I carried bottled drinking water in case anything went wrong in my main water tanks.
Do you really need it? Cost, maintenance and breakdown are big deterrents.
Pierre

 

[Terry Cox]

Anecdote; using a water maker in harbors/bays, etc., tends to clog the units. Best if used in the open ocean away from shore contaminants. Karen Thorndike's boat, that she sailed around the world, had a 30 gallon water tank. She told me that even during her longest leg of 90 days, she never ran out of water. She also said we're way over washed.

Our boat has 150 gallons of water. I use a PUR faucet filter for drinking, but even so our tank water tastes and smells fresh. And I detest bottled water; just a waste of money with no value added, IMHO. Our municipal water comes from the Sultan rain/snow melt watershed and always tastes delicious, unlike from other precincts like Texas, Florida, California, to name a few.

 

[justsomeguy]

never underestimate demand.

Ayup.

 

[RoyS]

Washing dishes consumes the most fresh water on my boat. BTW I added a 25 gallon bladder type auxiliary tank last year as a back up for my 50 gallon main tank and found we needed to use it on one trip last year. Cheap water backup, that.