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Hi Daria, I wrote this a few years ago for another venue. Dick
Hi all,
In a private comm, I was asked my thoughts with regard to watermakers, so I pulled together my comments from the past.
Watermakers:
Watermakers (WM) are, to my mind and experience, not essential to any adequately equipped cruising boat: fresh water is generally, these days, pretty easy to come by. The few occasions you might have to pay certainly does not compare to the cost of the w/m, not to mention the attendant installation and maintenance and power draw when running a WM. You might have to go out of your way to find water, though.
That said, having a WM in southern waters (Central America, Caribbean, Bahamas, The Mediterranean) was a wonderful convenience and tipped the scales away from “camping” in a way that I really appreciated. This, in large part, is because we were almost exclusively at anchor. In northern waters (Northern Europe, Canada), we have been on town wharfs and marinas etc. frequently enough so that we have not needed to use our WM in ~~8 years (we use it periodically to keep it functional). These areas, we have also not worried about quality: it has been universally good. I charcoal filter all water before it goes into the tanks, for taste and to keep any possible sediment out of the tanks.
A word about water usage. We lived without a WM for years in areas without good water. We collected water on deck (amazingly easy and functional on many boats including ours, a Valiant 42), but generally just got it where we could. Guests always killed us and it was after a Christmas with 3 children that we bought water, our one and only time. So, we learned to be careful, but, be sure, even conserving, we were in no way “camping”: we were quite comfortable.
In waters where we swam a few times a day, our before-dinner ritual was a swim which included soap and shampoo. A WM allowed us to feel comfortable having an on-deck (with an extended shower hose) fresh water rinse-off of the salt which was a lovely luxury. At that point we were using 3g per day (crew of 2) which (see below) translated into one hour of WM running every 2 days. This also gybed well as WMs like to be used regularly and a 2-day interim meant that there was no wasted water: at start the water made was good. (A longer break between operation would mean that the first water out of the membrane would be a bit smelly and thrown away). With other WM manufacturers (than Katadyne, see below), those with many bells and whistles that do everything for you: this could be up to a quart or more of wasted water each running. When left for longer periods (dirty anchorages, marinas) we would run the WM till the water did not smell (~~1/2 quart depending) and then taste it. Hands on admittedly, but worked fine and allows for a much simpler WM unit.
So, our water use is on the low side for many cruisers, but in no way were we deprived or compromised in life style.
Alchemy’s WM is a Katadyne (aka PUR in the past) 160E, the biggest unit made in 2003 (may still be) and modular. I shoe-horned it in the space behind the port aft settee cushion with the sea water feed going through 30 and then 5-micron filters and then to the pump (now I might consider a petrochemical filter as some anchorages were dirty in that way, but I have not explored their efficacy.) I draw off a thru-hull deep in the bilge that precludes contaminants that float and contributes to good sea water: but I am aware that oil etc. can be anywhere and was careful. It can fill either tank via a diverter valve.
It has worked flawlessly and for 3-4 years was almost our sole supplier of water for 6 months a year and periodically since then. It has had one re-build, maybe not necessary, but we were in the vicinity of where it could be easily done in England. I thought they would condemn the membrane, but they said it was still good. Very little use the last 10 years.
The Katadyne units are no-frills units. There are none of the bells and whistles that I hear being bandied about with the major brands. For example: initial-made water is collected manually in a tub and after a few minutes we put it in a cup and taste it. If good (always was) we divert it into the chosen tank. (Even this was unnecessary if we had made water within the last 2 days.) More sophisticated units do this for you: often at the expense of wasting water and certainly at greater monetary expense initially and providing one more thing to go wrong.
Also, there is no “back-flush” nor other add-ons. I am unsure what they contribute, but I know friends have talked about their added maintenance even to the point of keeping their units going in winter storage (in warmer climes).
It should be said that Katadyne is more expensive amp-wise to run: the amps per gallon is higher than the more sophisticated units. For my unit, it needed 20A/12v to run and made ~~6-7 gph. Fewer amps per gallon sounds great, but in practice may not make much difference. I have a DC generator which needed regular running anyway. Then there were those occasions where I powered a few hours and could just leave the WM going. This provided water the majority of the time and occasionally, I just ran it off the battery bank, but not often.
Were I to start over again, I would still use Katadyne, but would opt for the PowerSurvivor 40E model (also able to be used by hand/manually) and use two of them: one for each water tank. This would provide redundancy and would ease installation, even though installing 2 WMs, as this model is far smaller and not modular which cuts down on the connections considerably. I would run one day and the other the next.
The advantages are redundancy (especially for those dependent on r/o water, such as a long offshore passage). The manual operation could come in handy in an emergency. Each unit would fit snuggly behind the settee cushions in that triangular space (for V-42s) just above the water tanks. Being small and not modular, were repairs necessary this smaller self- contained package could be easily sent for repairs. A huge advantage is size: many sophisticated units are far far bigger.
The disadvantages are few: more amps used per gallon made and fewer gallons per run time: neither a big deal from my point of view, but as your fresh water use escalates, these disadvantages gain in importance. This is offset, again to my mind, by Katadyne’s utter simplicity: turn it on and it makes water. Use it every few days (depends on ambient air and water temperature, warm air/water every 2-3 days, cold air/water 5-7 days) and that is all. Pickling it takes mixing a biocide into a gallon of water and running it through the unit. Done and dusted for one year.
Come back with questions/comments/ etc.
My best, Dick Stevenson, s/v Alchemy