Watermaker

[rgranger]

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?

I've been researching the idea of using a 12V RV dehumidifier to make water. No holes in the boat.... and they are much less expensive and don't use that much power. The "wall" I've been hitting is capacity. The better units are still only making about a half gallon a day under optimal conditions.

 

[Kings Gambit]

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.

Seventy-five gallons of “tank water” has lasted us two weeks + with four aboard. Dish washing using seawater except for a final FW rinse (i.e., briefly submerge in sink). Drinking water is separate. It’s not difficult to conserve on daily water use for a couple of weeks, but doing so longer, into a month or more, takes some of the enjoyment (relaxation) out of longer periods away from services.

Some folks going to MX (Baja) have strongly recommend watermakers as some marinas there are now charging for water. Drought and otherwise arid/semi-arid conditions abound here on the west coast; California has statewide water restrictions in place. Every household, it seems, is under “pressure” (varying intensities) to reduce water consumption. The last time we charter-cruised BC (2017) water was rationed to something < 200 liters (if memory serves) per “fill” at places (six aboard on that cruise).

Having to “hunt down” scarce or rationed water, pay for it, and possibly lug it back, is not “vacationesque” in my view. A yacht’s “endurance” is defined by how many days/weeks/months it can remain away from services. A two- or three-week-long crossing of ocean waters is not long compared to lying at anchor at remote destinations for, say, six weeks to a couple of months; even more. Power (e.g., fuel), water, and provisions are the basic components of endurance. For a sailboat, the most limiting component generally appears to be water. From that perspective a watermaker appears a good and sound investment in one’s recreational use of the yacht. A decent sized yacht can easily carry six months of provisions. Solar power is potentially unlimited; plus you have the wind for moving about. Six months of water supply would be tough w/o a watermaker.

 

[Rick D]

When we are in Ensenada for a month, 105 gallons lasts for three weeks + if we don't shower aboard. Most of that water is dish washing, dog washing, an occasional shower aboard, and coffee. If we get low, we have the marina bring in purified water in what I think are in 20 liter jugs. You do need a good funnel or half will wind up on the deck. If we were in an anchorage, a watermaker would be a serious plus.

 

[dLj]

Six months of water supply would be tough w/o a watermaker.

If you are looking for that kind of self-sufficiency - a watermaker is almost a must, especially if you are in arid regions where you can't catch rain. Well, there is almost no rain to catch...

SV Soggy Paws did a nice presentation on making a water maker. You can buy one or make one, but this presentation is about making one. I listened to him give a talk on this a few years ago - it's a little dated now but not too bad. He made a point that it's really nice to make a lot more water faster rather than slower - means you run the device for much shorter periods of time and that way it's easier to manage the power consumption. The other side of that coin is running a slow one a lot of the time, but you can probably do it off solar panels. But He was making the point that if they are in a a dirty port somewhere and can't run the water maker, then they can just go out for an afternoon day sail and make plenty of water... Like everything sailing, ya pays your nickels and ya takes your choices... everything is a compromise...

http://svsoggypaws.com/files/presentations/Making_Your_Own_Watermaker-Dave_McCampbell.pdf

dj

 

[Hollyberry]

A couple of years ago we did a month long cruise with friends (on their GB 42) to the remote central coast of BC.. prior to departure we installed a watermaker.

Here on the south BC coast water is usually easy to find (and free) but the last two summers have been hard on water supplies, esp on islands even here. Up north water sources are far and few between, and GOOD water sources scarcer still. The watermaker was a game changer.

Our hosts showered every day, the 30gal/hr watermaker was run every two or three days. Only downside was - with a 120V high pressure pump, the generator had to be running at the same time.

 

[desodave]

There's lots of watermaker threads on the Cruisers Forum and some very knowledgeable people :

Plumbing Systems and Fixtures - Cruisers & Sailing Forums

Plumbing Systems and Fixtures - Freshwater systems , Watermakers, Waste systems, fixtures, HVAC & Refrigeration

www.cruisersforum.com

We recently bought a new to us boat with one already installed. No additional through-hulls with input T-ed off the head intake and output waste into the vanity drain as suggested above. But in a full season, we've hardly used it. I think they suit the longer expedition much better. Our 100 USG tanks last us about 10 days and, while we anchor out mostly, we're usually on a dock somewhere during a 2 or 3 week trip and can pick up water easily. I think there's places you don't really want to run a watermaker because of the quality of the seawater imo, and that may include crowded summer anchorages. I also have concerns about a constant water supply while underway ... our electric head feed pump will not draw water while underway at our normal motoring speed, about 7 knots. There should probably be a scoop on the through-hull to solve that issue but ... unfortunately ... the through-hull is also very close to where the slings go on a haulout, and I'm not sure how long it would last.

 

[RoyS]

Another long distance cruise issue is trash accumulation. How do you long distance cruisers handle that?

 

[jssailem]

Wow, Roy that is a query that likely deserves it’s own thread.

 

[Hollyberry]

....... I also have concerns about a constant water supply while underway ... our electric head feed pump will not draw water while underway at our normal motoring speed, about 7 knots.....

On the Grand Banks we found above 5 knots the feed pump cavitated too. It might be changed to a scoop as it's a dedicated throughhull.

Carefully choosing your watermaking location is certainly an issue...

 

[Kings Gambit]

Wow, Roy that is a query that likely deserves it’s own thread.

Probably so. But here we’re not specifically talking “long distance” cruising; rather, time away from shore-side services. How trash, garbage, or waste is disposed would depend on one’s location and regulations appertaining. Depending on distance from shore garbage (food stuffs) and waste can be discarded overboard. Trash, excepting plastics, can be weighted and sunk. In some circumstances it might be incinerated ashore (e.g., burned on a beach). Ultimately, trash might be compacted and stowed aboard. It does not increase in size or mass; if it can be brought aboard it can be stowed aboard. The trick is to minimize the amount of disposable packaging material brought aboard in the first place.