Watermaker advice required

Bilge Rat

Bilge Rat

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Hi All,

Wife of Bilge Rat here.

We start our cruising adventure next spring (UK to Med for year one) and we plan to visit the Southampton boat show to research one of two bits of kit that we would like to have aboard (if we can afford them), one of which is a water maker.

I have read a couple of articles on the pros and cons of AC versus DC and engine driven models and those with a power recovery system versus not............ So lots of options but which ones would suit our cruising yacht best?

We sail a Nicholson 39 (with 500 litre water capacity) and would prefer an efficient 12 volt or engine driven system as power will be something we need to manage carefully (if the beer is to remain cold!)

So my questions are...

How do I confirm what will suit us best?
Which models in use get the liveaboard "thumbs up"?

Any help or advice will enable me to identify suitable suppliers at the show to talk to.

Thanks a million

Jackie
 
The ideal solution depends on many factors however here a few things to consider:

Where are you planning to cruise and how much motoring or motorsailing do you envisage? If heading for the Med you will do more motoring than you think. If you are going to do a reasonable amount of motoring then an engine driven system will be best. A system with one 40" membrane will produce about 60 - 70 ltrs an hour so if you are going to be motoring for an hour or more every second or third day then you will be able to make plenty of water for two of you to have enough water for cooking, showers, washing etc. We use around 40 ltrs per day on average for two of us without being too careful about useage.

You need to run the unit every second or third day to prevent bacterial growth etc, if you leave it any longer then you must flush with fresh product water (that takes time to make), this will allow up to 7 days before it needs reflushing, any longer and you need to pickle the system. With an engine driven system you can run it regualrly for 30 or 40 mins.

Energy recovery systems are much more expensive, typically twice the price for equivalent outputs. You must be sure that your charging systems will cope with the current draw so you will need a reasonable amount of solar panels and a good size battery bank. If you are going to rely on engine alternator for charging then you might as well fit an engine driven system.

EchoTec supply full kits for self installation and they use standard industrial components so spares are cheaper and generally easier to get. A single membrane system is as big as you can safely go with an engine driven pump driven by a single V belt, any bigger a system and you need double belts that will add cost and complexity to the installation.

AC driven systems only make sense if you already have a generator installed on board, if so then 240 V AC will generally be the cheapest and most cost effective type to choose.
 
As said you you will motor a lot in the Med, so no problem with making water. With the size of tank you have you don't really need a watermaker unless you are going out in the boonies for months or on ocean passages, which is why we had one.

If you do buy one don't buy a Spectra, they have bespoke parts and chemicals. Water makers are simple things and other makes parts and chemicals can be bought off the shelf anywhere in the world.
 
crisjones said:
The ideal solution depends on many factors however here a few things to consider:

Where are you planning to cruise and how much motoring or motorsailing do you envisage? If heading for the Med you will do more motoring than you think. If you are going to do a reasonable amount of motoring then an engine driven system will be best. A system with one 40" membrane will produce about 60 - 70 ltrs an hour so if you are going to be motoring for an hour or more every second or third day then you will be able to make plenty of water for two of you to have enough water for cooking, showers, washing etc. We use around 40 ltrs per day on average for two of us without being too careful about useage.

You need to run the unit every second or third day to prevent bacterial growth etc, if you leave it any longer then you must flush with fresh product water (that takes time to make), this will allow up to 7 days before it needs reflushing, any longer and you need to pickle the system. With an engine driven system you can run it regualrly for 30 or 40 mins.

Energy recovery systems are much more expensive, typically twice the price for equivalent outputs. You must be sure that your charging systems will cope with the current draw so you will need a reasonable amount of solar panels and a good size battery bank. If you are going to rely on engine alternator for charging then you might as well fit an engine driven system.

EchoTec supply full kits for self installation and they use standard industrial components so spares are cheaper and generally easier to get. A single membrane system is as big as you can safely go with an engine driven pump driven by a single V belt, any bigger a system and you need double belts that will add cost and complexity to the installation.

AC driven systems only make sense if you already have a generator installed on board, if so then 240 V AC will generally be the cheapest and most cost effective type to choose.
Click to expand...

Agree completely...for Med cruising, which is more motoring than sailing, certainly go with an engine driven HP pump. It can be mounted with an A/C-type electro-clutch to engage the pump. You will need a feed pump, HP lines, pressure gauge, membrane and membrane tube, and several manually operated valves.

I feel certain that you can get a water maker guy to build your system for you with off-the-shelf parts including a Filmtec SW30 Membrane. Don't buy some "packaged system" from someone like Spectra. Save your money...talk to several water maker people about custom building an engine-driven system for you. Go for 80 liters per hour which will be 1 each SW30-2540 Fimtec Membrane. If the water maker guy suggests a all-in-one-pre-fab system run away as fast as you can. After talking to 3 or 4 prospective installers, you will understand a lot more about this.

Plenty of fresh water makes everyone very happy.

Bill
 
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TQA makes a valid point by asking "Do you really need a watermaker?"

However when considering this you need to factor in your lifestyle and budget - while water can be found or bought anywhere you are likely to sail you need to consider the quality and the cost. Even in the Med some shoreside water supplies are undrinkable - we had a couple of reports from cruisers about certain places in the Balearics. With a watermaker on board you can spend long periods in remote anchorages - they can still be found even in the Med - you can also sit out periods of bad weather in snug anchorages without worrying about water.

The other factor is cost - probably fairly insignificant if you can go alongside, top up the tanks, pay for water and leave, but can get very expensive if you have to pay for a marina berth overnight as well as the cost of the water. This is fine if your budget includes regular nights in a marina but is very expensive otherwise a 39ft boat will cost between 60 and 100 euros per night, peak season in many central med marinas. These sort of fees will soon add up to significant amounts that can be saved if you have a watermaker.

The quality issue is also totally under your control with a watermaker - you should always have plenty of clean, fresh drinkable water rather than having to rely on dubious shoreside supplies. The other alternative is to use shoreside supplies for all but drinking and cooking and then buy bottled water. Even though bottled water is much cheaper in the Med than in the UK it will still add up and it is also alot of weight to carry from shops to boat.

I built our watermaker myself so it was considerably cheaper than buying a complete system, but it is worth every penny in terms of convenience and quality of supply. We have a catamaran so berthing fees above would probably be double for us in peak season so considerable money over a summer. We have not been into a marina for around 4 months and the watermaker has been a huge factor in this, also carrying jerry cans via dinghy can get a bit of pain if you opt for that method to avoid marina fees.

More and more cruisers are fitting watermakers even when cruising heavily populated areas like the Med - quality, convenience and marina fee savings are all significant factors in their decision.
 
crisjones said:
More and more cruisers are fitting watermakers even when cruising heavily populated areas like the Med - quality, convenience and marina fee savings are all significant factors in their decision.
Click to expand...

Chris,

One other benefit with you water maker on your cat is that you have reduced the weight you need to carry by reducing the onboard water to a day or two worth of water. This can be a big deal on some boats and especially cats.

Bill
 
Bill,

When you live on board a cruising cat then the weight difference of a couple of hundred litres of water is pretty insignificant when it is considered alongside all the other "essentials" that you carry as liveaboards.

We have a Broadblue 42 that was never intended to be a lightweight flyer, she is designed and built as a solid, comfortable cruiser and she performs that function admirably. We know we are overloaded and we just accept it as a consequence of being comfortable on board, we are generally not in a rush so the 1/2 to 1 knot speed penalty due to our extra weight is not significant to us - it may be to other cat sailors. We find that up to about 7knts the extra weight does not seem to have too much impact, above 7knts then the extra weight and wetted surface needs much more power to move through the water so we rarely get above 10knts unless surfing downwind!!! We can still average 6knts for most passages so we are happy enough.

I tend to keep the water tanks between 1/2 and 3/4 full (300 - 500 litres), this means we have plenty in reserve if we have any problems with the watermaker. The potential reduction of 250 - 350kgs weight is not enough to make a difference when we are only day sailing on short hops of 20nm or so, it may be worth considering on longer passages, but then so are all the clothes and shoes and tools and spares and anchors and warps and food and drinks etc etc!!!!
 
When we researched watermakers, we ended up choosing a Spectra as one factor was power usage - we do not have a diesel generator. There is not a lot to choose between the main brands. We have a manually operated unit and would advise against an automatic unit as we know people who have had a lot of trouble with them. Manual operation means sticking a pipe into the sink for afew minutes while the water quality becomes potable, checking the water quality with a hand held meter, then turning a valve to diverting water into the tank, and then turning a couple of valves to flush after making water. Our system requires usage every 5 days (or flushing) to avoid bacterial growth. We tend to run it every 2-3 days as this means a short time to replenish the tank

One of the big benefits of a watermaker is freedom - being free from going in search of water in marinas, docks etc; freedom from using jerrycans to dinghy water out to the boat at anchor; using as much as you want (we are quite frugal but shower daily); freedom from worry about the water quality that you put in your tanks.

Lay up procedures are quite straight forward.

We change the principal filter very regularly and they can be washed and re-used many times.
Enjoy
 
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Its understandable that people will focus on cost when deciding whether to buy a watermaker. I would add from our experience that you should very much focus on the convenience of having one. We can certainly hunt around and find water if we want to, sometimes without paying for a marina berth, but the freedom of not having to do that is worth more than you would imagine.
We have an EchoTec AC system which is currently giving us about 75l an hour. I can't say anything bad about EchoTec......yet.
 
We went through tis very questio ourselves this year..

We decided on the echoteck water maker... verey basic and easy to install as it comes in parts whichncan be mounted where we have the space..

Then the power supply choice...
Mounting the HP pump on the engine sounds easy... but is actually quite tricky.. If you have a 3 cylinder engine... it will have quite a lot of vibration.. the mounting bracket has to be very robust to avoid simply shaking itself to bits... It is also very fiddly to install... the belts have to be absolutley true to the pullies Etc... or you will simply burn out belts in a hurry..

because of this we decided to go with a DC driven unit powered from the alternator.. 55 amp..

Then we decided that in the Med we are probably never more than three days sail at a time from a harbour where we can fill up.. (even if we have to pay)..

Finally we are opting for a water filter on the tank.. but we will install a dedicated drinking water tap for the filted water.... This time next year we will tell you if it has worked???
 
One thing that hasn't been mentioned so far is space.
Where will you fit a watermaker? If you are cruising the Med than you'll not really need one. As has been mentioned you will spend quite some time motoring, motoring means filling with diesel. If you fill with diesel then you'll top up with water at the same time!

We fitted one because we were going further afield, we used it in the Canaries. That's all!
The Balearics have a certain reputation but cruising there for several years we never found any problem filling with usable water, obviously check before filling tanks. A water filter would be a cheaper option.
Our tankage is 500ltr which lasts 1 month when cruising. We have appx 100ltr capacity in plastic 8ltr bottles which are filled and used for showering using a garden pest spray for after swimming. They are taken ashore and topped up when necessary.
Also don't forget that the filters for a watermaker will need changing fairly regularly especially in shallow water/contaminated areas.
If you have the space and are going to spend long periods away from 'civilisation' then a watermaker is probably the way to go.
 
We use on our Hallberg-Rassy 39 an automatic AC watermaker from Tecnicomar/Italy together with an automatic flushsystem almost daily since April 2009 without any problems. To flush the system there is no need for produced water, a filter takes the chlor out of the shoreside water when flushing. This AC unit has the advantage that we can run the washing machine when making water the same time and heat as well the hotwatertank or do cooking. The Minimar 600/ 100 Liter/h cost us complete with remote controls 7.200 €, ordered directly from Tecnicomar and that is a very competetive price from an experienced producer. We were asking them for a 12 V DC system first, but when they heard that we own a Dieselgenerator they did not even make an offer for a DC system, by their opinion DC systems will bring energy problems. This year dutch friends here in the Canaries bought an Echo 12 Volt unit, it did not take long and they had to run their dieselgenerator to get enough electricity, they had as well solarcells and a windgenerator but the watermaker draw for almost 50 Liter 40 Amps, too much.

Don´t go with 12 Volt, if a dieselgenerator (there are nice quite FisherPandas in the market with extra waterseparators to reduce noise) is out of question, go with an engine driven system.

We never had better water on the boat.

BR Klaus
 
Last edited:
As Annabell says you can use a carbon filter to make shoreside water suitable for flushing a watermaker system, but you have a watermaker!!!

I would always use product water for flushing in preference to filtered mains water, although if you cannot make water due to dirty seawater then obviously you are limited to filtered mains for flushing.
 
Hi Everyone, Thanks for such good advice.

Our own experience of taking on board water in Porto Heli (Greece) some time ago was that it was not fit to drink...... and friends were turned away from a full marina in Mahon during July when all they wanted to do was come alongside to take on board water. I really like the idea of having consistently good water quality aboard and not risking an upset stomach. avoiding un-necessary and costly marina stays during peak season would be a real bonus. Finally I have to confess how shallow I am.....I am not that keen on the idea of lugging water back to the boat, I will save my strength for lugging the beer and wine.

We only have a small petrol generator that will top up batteries and give us a tank of hot water but other than than we are dependent on 190 watts of solar and a wind generator plus the engine.

I think from all the comments posted that our lead option should be an engine driven water maker................ I really like the idea of svaing some money and building this ourselves as per Chris' suggestion. Bilge Rat is very practical and just loves a challenge.

Thanks again.

Jackie
 
We've been weighing up the idea of a watermaker also. Having read through this thread, I Googled Echotec just to see what we should be budgeting if we were going to go with a pre-built unit. OUCH!!!! $4950 for the smallest unit. I then started hunting around and the cheapest all in one package/unit I found was still almost $3000. Based on the average $25 Euro's a night we were paying in Greece and Turkey (many places in Greece charged nothing to moor, and just a few Euro for water, that's several seasons of cruising for us (we hold almost 500Ltrs, so can go for a number of days without needing to refill).

The idea of building our own unit seemed like something to look into, and minus any suggestions in this thread for where to source the elements, I fell back to Google again. I found this link which I offer up for comments from the folk that have done it already.

http://underwaterprojects.741.com/myfiles/Build Your Own Watermaker.pdf

I looked up the example of the Belt Driven High Pressure pump that is mentioned in the document, and discovered that it is available for $295 online. That leaves a considerable surplus from the cheapest package for the membrane, filters and lines.

Can anyone provide info on the other bits of kit needed?

Cheers, PT.
 
This website http://sublimesustenance.files.wordpress.com/2012/03/how-to-build-your-own-watermaker.pdf gives a more detailed insight into the process and parts required to build your own watermaker, also gives sources for most parts.

In the UK, Screwfix are good for pre filters and filter housings, asap-supplies are good for nylon high pressure hydraulic steering system piping and fittings that are ideal for the high pressure side of a watermaker system, desal.co.uk are a good source for membranes and pressure vessels, as well as bulk supplies of pre-filter cartridges. Finally CAT Pumps have a UK dealership. Google will find all the above as well as many alternatives - you need to do a bit of work yourselves!!!
 
PhilipH said:
When we researched watermakers, we ended up choosing a Spectra as one factor was power usage - we do not have a diesel generator. There is not a lot to choose between the main brands. We have a manually operated unit and would advise against an automatic unit as we know people who have had a lot of trouble with them. Manual operation means sticking a pipe into the sink for afew minutes while the water quality becomes potable, checking the water quality with a hand held meter, then turning a valve to diverting water into the tank, and then turning a couple of valves to flush after making water. Our system requires usage every 5 days (or flushing) to avoid bacterial growth. We tend to run it every 2-3 days as this means a short time to replenish the tank

One of the big benefits of a watermaker is freedom - being free from going in search of water in marinas, docks etc; freedom from using jerrycans to dinghy water out to the boat at anchor; using as much as you want (we are quite frugal but shower daily); freedom from worry about the water quality that you put in your tanks.

Lay up procedures are quite straight forward.

We change the principal filter very regularly and they can be washed and re-used many times.
Enjoy
Click to expand...
Spectra enjoys superior brand loyalty, no doubt about it. But, wait until you need to replace those Spectra Membranes which are made by Filmtec, but only available from Spectra...I am betting that your brand appreciation level will change when you pay as much as 3 times the going rate for membranes.

It is my informed position that Spectra engineers the membrane tubes slightly longer or shorter. Spectra contracts with Filmtec to manufacturer a "membrane to Spectra specs." The only difference in specs is the length which is +- 1". The agreement Spectra has with Filmtec is that Filmtec only sells this to Spectra. Now, why do you think Spectra does this? This is not the only example of Spectra attempting to cage their customers...think about it.

Incidentally, last night I had sundowners on another boat anchored near me. He said that he only makes water when he is motoring. I asked if he had an engine drive system. He said no, 12 volt. I looked a little surprised. He said that when he bought the pre-packaged system from a name brand company that he was told that his 60l/hr system would only consume 12 amps, but, in fact, it is consuming 40 amps. He only makes water when he is motoring because of the high amp draw. He said he contacted the manufacturer and that they told him that they were aware of the high amp problem and their engineers were working on it...that was 1 year ago according to him.


Bill
 
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