Which Watermaker To Choose

[wolfenzee]

Forum reviews:

http://www.cruisersforum.com/forums/...log-12804.html
Waterlog watermaker - SailNet Community

From what I can see disadvantages/problems complained about
(1) skips over water at speeds faster than my boat is capable of (hull speed = 6.75kt)
(2) doesn't stay submerged (a foil has been added to counter that
(3)Only produces 24gpd ( fine for a crew of 2)
(4) doesn't produce water at slow speeds
(5) only works when boat is moving.

I have here both good and bad performance results. I would use it to supplement the tankage on my boat, not as my primary source of water and before.I get one I would like to see one and talk to someone who actually has one.

[Pelagic]

This has been a great thread with one repeating constant… All cruisers who have replaced their R/O system have generally upsized a bit, if practical…., exception being spectra type, who as Nolex confirms, just runs longer then deals with power management.

One issue not really discussed for cruising in remote areas with no local support is the Redundancy factor of Power Sources in choosing an R/o System

1. Main Engine Driven: Cheapest acquisition cost but only one primary mover to create water. If ME is down, you have 2 problems!
   
   
2. AC Electric: Dependent on either an AC Generator or Invertor. So 2 available Power Sources… which is better, but if Invertor is down, you have no battery power source!
   
   
3. DC Electric: Primary Power Sources to maintain Battery from a) Generator b)ME large Case Alternator c) Solar d)Wind e)Shaft Gen so that has 5 x Redundancy to drive pump, but in some cases you will be limited by battery charge capacity.

While I like Spectra, I imagine it would be hard/expensive to replace, repair components in Asia/Oceana. I also will not leave the boat if the R/o is running, so I wanted higher hourly capacity,still 24v but with locally repairable/replaceable components

So I have ordered from Rich (Cruise RO water) a 24v system and he has been great to work with.

[goboatingnow]

Originally Posted by wolfenzee

There used to be a watermaker powered by a tow behind prop, like a knot log....name brand was "Water Log"......no electricity needed.

Your right there used to be , it didnt work. ( well )

Dave

[downunder]

Originally Posted by wolfenzee

Found it (after the time limit for editing was over). The are made in the UK, cost is 1200GBP/$1936US, they produce 24gpd with a permanent filter. This is more than adequate to keep up with the water needs of a crew of 2 (manufacturer says 2-4), experienced cruisers I have talked to use 3-5gpd/person tops, you can just tow this till your tanks are topped of. This is just a very simple, inexpensive alternative.
Waterlog the only water-powered watermaker in the world

Do not hear too many expounding their virtues.

[delmarrey]

It might make a good watergen if one could keep the prop below water.

[Tellie]

I've been following with interest this thread.
What I will say is what I've always said hundreds of times. "There is no one/size watermaker to fit all'. I think that many here have done a good bit of research and have come to some very good conclusions of what they think will best work for them. But that does not translate into gospel for what will work for another. I usually spend hours on the phone or by E-mail talking to people who are considering getting a watermaker for their boat. The one common thing between all of them is that there is no commonality between them. One may want an AC driven system but the DC system is a better fit and vice versa. Choosing a watermaker based on price is the first most common mistake most first time buyers make. The first question the majority of people ask me is "What is the smallest and cheapest watermaker you have" I've always wanted to hand them a shovel and a divining rod cut from a tree out back. I will say this from long and hard won experience is that almost anything under 5-6gph is a waste of good money for todays modern cruiser. Make no mistake, it is just as easy to get a watermaker that is too small as it is to get one that is too big. Heck, if gallons per hour and energy efficiency is the goal I can get you into a 75 gallon per hour watermaker that only uses 1000watts, Boys that's only 7.5amp hours. I'll even sell you two of them for 150 gallons an hour and you can run them both off that single Honda EU2000. Why in no time at all you can fill both of your 50 gallon on board tanks and be the envy of every boat in the anchorage. You could save a ton of cash and buy a 1 gph watermaker with a string attached. But if you've ever done any real or extensive cruising you can quickly figure out how many 24 hours of constant movement you boat does in a year and the math just don't work so good. Even if it did, running it for 24 hours? Really, seriously? It's a boat. What other system can you run the dog s*%#t out of and expect it to last? Lastly, why would you talk to a salesman? You know, the guy that has probably sold, installed, maintained, owned, serviced, repaired and is probably a cruiser like yourself, more watermakers than you? I think Rich will back me in this when I say we don't do this to get wealthy we do it because we are just like you and enjoy helping others. We're not selling used cars. Buying a watermaker is really the Goldilocks approach. Not too small and not too big, but rather just right for you. Carry on.

[CAELESTIS]

Lots of great ideas on this thread. For those that are factoring cost as a primary consideration, don't forget to include the cost of the power generation system, such as a Honda EU 2000. I already have one but find it excessively generates noise.

[daddle]

Originally Posted by Tellie

... Heck, if gallons per hour and energy efficiency is the goal I can get you into a 75 gallon per hour watermaker that only uses 1000watts, Boys that's only 7.5amp hours.

1000 watts is more like 80 amp-hours for the typical cruiser. In the loose speak of CF.

I have not heard any persuasive arguments against my desire for a quiet low volume continuous operating watermaker. The only good point made somewhere above was about bring anchored for extended periods in an area of unsuitable water. I feel that much of that might be ameliorated by either changing filters more often or having filters of a suitable capacity. Or moving on...

[Tellie]

Originally Posted by daddle

1000 watts is more like 80 amp-hours for the typical cruiser. In the loose speak of CF.

I have not heard any persuasive arguments against my desire for a quiet low volume continuous operating watermaker. The only good point made somewhere above was about bring anchored for extended periods in an area of unsuitable water. I feel that much of that might be ameliorated by either changing filters more often or having filters of a suitable capacity. Or moving on...

Yes at 12V, not at 120V provided by the EU2000. You stated earlier that what is important for you is the energy used to make one liter or one gallon. Actually that makes it a lot easier to understand because that's really the figure most people who are going 12Volt need to look at. Slow or fast producing doesn't mean much until you figure in not only energy used to make that liter/gallon but how you are going to replace that energy. Running your engine is great and will usually put out far more energy than a 12V system will require. But that leaves the owner with two choices, make water while motoring underway or running the engines at anchor to make water. Sounds simple enough in theory but reality has a tendency to get in the way. I won't even get into the debate about running diesels at anchor to charge batteries or run watermakers under low loads. In my experience it's a no no. Most watermaker installations are not the same. As an example I just installed a unit four weeks ago on a Cat where the owner insisted on using an existing thru hull forward of the keel about 2' below the waterline and this happens all the time. Owners get stubborn about new thru hulls. I couldn't convince him otherwise. Cats hobby horse and most watermakers don't do well with air ingress. So making water while motor sailing is not an option for him until he installs another thru hull. Poor installations issues abound. Certainly most are correctable but it usually adds cost. If a small 3.4gph watermaker uses 2.5 amps to make one gallon of water why would someone not consider, for about the price of one solar panel more, a unit that makes 6-7 gph that uses half the amps to make the same gallon of water? It could be run for half the time and use half the energy and again I don't care whose watermaker it is, long run times mean wear and tear and long term costs for repairs and rebuilds. These figures are for the most part left out of the total cost equation.

[goboatingnow]

I dont see the complexity of this part of the debate,

If you have AC or a systen thats requires an engine to be run, then the largest water maker you can afford consistent with the tankage, is the best decision. If you wish to run on DC, then you have a simple decision based on the availability of charging sources and a balance between that an run time. Since in practice the largest practical motor on DC is about 1.25HP,( without energy recovery) that a limiting factor anyway.

I dont see the advantage of specifying a proportionally smaller watermaker then you can run , unless you are getting a serious cost reduction, why extend your watermaking period for no real gain, you will still use up the wattage anyway.

Dave

dave

[ka4wja]

I can't believe that this thread is still going!!!

1) As I wrote weeks ago, I own and love my Spectra Ventura MPC-5000 (working great for > 6 years and >12,000 miles offshore), and I have also stated my appreciation for Rich's (Cruise RO) larger units...
I think either of these are fine choices, depending on your specific application and your on-board energy generation/storage....

And, I also pointed out quite bluntly what some have been dancing around....that "watermaker decisions" are very subjective, and should be based on YOUR needs/desires, and most importantly on what your on-board energy generation and storage capabilities are!!!

I think most of the above is accepted my most of those here....
And, together with Tellie, Pelagic, Nolex, Colemj, etc. we have discussed this in detail....so, I'm sure what else there is for me to say....




2) And, while I thank Mark (colemj) for relating his experiences, and agree with a lot of what he wrote, I do have a couple questions/clarifications....

Originally Posted by colemj

You will still need a running charging source to meet output specs because these units are spec'd at 13.8V.

I cannot speak for other brands, but Spectra publishes their product output specs at the nominal battery voltage of 12vdc(or 24vdc) not 13.8vdc....
My Spectra Ventura's specs for its "rated output" are actually shown at 12vdc (and 77*F seawater temps), at 6.3gal/hour (150gal/day)....
Spectra Watermakers - Marine Watermakers - Ventura 150


And, for more than 6 years, I have found significantly higher product output of 6.9 gal/hr - 7.4 gal/hr (depending on battery voltage and seawater temp), and I generally figure on an average of 7gal/hr at about 8 - 8.5 amps of current draw....)
Watermaker
4706109





3) Regarding the relative pricing of the various units.....I'm a bit confused, as I see little difference in the actual prices, although there are large differences in the "price per gal/hr".....

Originally Posted by colemj

.... I agree that if one has sufficient solar/wind, one can run a lower output DC system for long periods of time. However, this isn't really practical unless one has an energy recovery system. These are VERY expensive and another debate altogether. It really is about amps per gallon, but the price wall makes the decision complicated.
If money is no object and one has enough wind/solar to provide daily energy PLUS water (and you know this is true from actual experience with your usage and systems and not a paper calculation), then I agree that a Spectra/Schenker makes sense.

I find the Spectra Ventura 150 selling for about $5000 (a bit less if you get a "boat show discount"...and Rich's Cruise RO units selling for about $4200 (20 gal/hr) and $5000 (30 gal/hr)....
Ventura 150 and 200 Series Watermakers
20 GPH Water Maker
30 GPH Water Maker

So, I am confused by the statements that these "energy recovery" units are VERY expensive.....
Yes, the bigger units are more expensive....the Newport 400 is about $7700 and the bigger 700 is > $10k.....
But, the point is that with these high-efficiency / "energy recovery" units, you CAN use a lower-capacity unit (approx. 7-8 gal/hr) and they CAN be run for longer periods of time, using solar-charged battery power, etc. and the "larger capacity units" are not needed....

So, if you compare watermakers by what they'll actually produce for you, on your boat, using your energy systems, over the day/week/etc. and the energy they use over the course of the day/week/etc. to produce that water, then in MY opinion, you may see that the Spectra's are not that pricey after all...or not...
Again, I'm not disputing what Mark has experienced, I'm just writing what I have experienced and noting that if someone does have the energy capacity to run a unit for a longer period of time (twice as long in most cases), then a lower capacity unit (7-8 gal/hr) energy-recovery unit can make sense...

{Add a couple grand for the fully-automatic MPC-5000 system for the little Ventura and it does add up a bit....but then you're not comparing apples to apples....and aside from a couple defective salinity probes, I've never had any problems with any of the "automatic" functions....but if I do, there is ONE toggle switch to flick and then she's in manual mode.....
I'm not sure about all those guys Mark has met who are "constantly fighting them", but perhaps they have some "installation issues" etc. that may be causing these troubles as I have had my Spectra for >6 years, > 12,000 miles offshore (incl two Atlantic crossings) and haven't found these issues at all...}

I'm not disputing what Mark has experienced, and take him at his word, but rather, I'm just saying that there are a couple different ways to compare things....
And, if take into account that you CAN use a smaller capacity energy-recovery unit (running for a longer period of time), then you may find that the "cost difference" to be slight....

Understand that I still feel that YOUR watermaker choice should be based on YOUR application/use, and on YOUR on-board energy generation/storage capability.....
I'm just saying that IF you do have adequate energy capacity (solar/batteries/etc.) then a smaller capacity (7-8 gal/hr) energy-recovery unit is not anymore expensive than a larger capacity AC-powered unit, and it CAN be a viable choice.....(it works well for me!!)


And, yes, having the energy to run a watermaker (whether DC, AC or engine driven), IN ADDITION to your other systems on-board, is very important and should always be considered.....
Solar Panels
Towed-Water-Generator
Battery
Watermaker



Also, in addition to running it when offshore and in the Caribbean, I have run my unit in the Bahamas (mostly the Exumas, Berrys, and Long island) and have not found any issues with clogging filters....but since I'm in a bit deeper water (as I draw 6.5') and have my RO raw-water intake ~ 2' - 2.5' below waterline, I haven't noticed problems with silt in the filters nor had any issues with sea grass, etc. there in the Bahamas....
But, right here at my dock in S. FL I have lots of silt in the water (I'm about 2 miles up river from the St. Lucie inlet) and my pre-filters will start to fill up with silt in just a few hours, so I DO understand Mark's issue when in areas of high silt....




Fair winds to all....

John
s/v Annie Laurie

[Matt Johnson]

Tellie,

Speaking of thru hulls, what do you think about the forward facing thru-hull scoops recommended by some watermaker companies? HRO recommends having a forward facing scoop, but never got an answer from them if it's necessary for fast moving vessels or something as slow as our sailboat. When I installed the unit, I put in a new 3/4" thru hull, but not the scoop as I'm worried about the flow when the system is off and we are still moving. It's not a seacock I typically close unless we are leaving the boat for a long time.

[mcarling]

Originally Posted by goboatingnow

I dont see the advantage of specifying a proportionally smaller watermaker then you can run , unless you are getting a serious cost reduction, why extend your watermaking period for no real gain, you will still use up the wattage anyway.

Playing devil's advocate for a minute, how about weight as an advantage for the smaller units?

[goboatingnow]

Originally Posted by mcarling

Playing devil's advocate for a minute, how about weight as an advantage for the smaller units?

Sure all the boats on CF are huge anyway!! ( and long keeled , what weight)

dave

[Tellie]

Originally Posted by funjohnson

Tellie,

Speaking of thru hulls, what do you think about the forward facing thru-hull scoops recommended by some watermaker companies? HRO recommends having a forward facing scoop, but never got an answer from them if it's necessary for fast moving vessels or something as slow as our sailboat. When I installed the unit, I put in a new 3/4" thru hull, but not the scoop as I'm worried about the flow when the system is off and we are still moving. It's not a seacock I typically close unless we are leaving the boat for a long time.

Actually for faster moving boats it is recommended even more but recommended for slower moving boats as well. There is actually some positive pressure gained with forward facing scoops which helps many systems run a bit easier. The positive pressure created when the water maker is not in use wouldn't be enough top overcome the unit and slowly flush the system with salt water if that's what you mean? But with many systems using only a straight thru hull there can be a vacuum created as the water passes over the entrance to the thru hull much like the effect caused blowing across a straw in a glass of water. Some watermaker companies require a forward facing thru hull for warranty purposes as well so make sure you check.