An introduction to watermakers for yachts

With thanks to VDM - Reya, Astilleros de Mallorca and Sea Recovery

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While water management systems are vital to the smooth and cost-effective running of superyachts, they must operate seamlessly, effectively and without hassle. With a huge demand for fresh water for showers, baths, food preparation, laundry, washing down, etc. superyachts need to be able to produce their own fresh water through desalination.

Find suppliers of yacht watermakers in your area here

Having a yacht watermaker (also known as reverse osmosis desalination systems) on board is a huge advantage because of the reduced need to have large, heavy water tanks on board for long charters. Depending on the design, superyacht watermakers can be powered by electricity from the battery bank, an engine, or an AC generator. 

The importance of a yacht watermaker

Astilleros de Mallorca commented, "First and foremost safety should be a paramount concern. When you consider the average superyacht passenger can consume anywhere from 30 gallons of water to 100 gallons of water per day, having a fully functional and quality watermaker on board, greatly limits the potential risk to crew and passengers by providing virtually limitless fresh water. This becomes even more essential in the event of an emergency that keeps a superyacht offshore for an extended period of time. This provides both crew and passengers with peace of mind."

Having the ability to make fresh water while you are underway frees the superyacht from the burden of carrying the water weight necessary to accommodate an entire voyage. Consider this, water weighs approximately 10 pounds per UK gallon (8.3 per US gallon) this extra weight adds up and can reduce the distance you can travel over a given period of time. It is also worth considering that if the superyacht is power driven, fuel costs will increase according to the additional weight carried on the journey.

How much water do you need?

There are plenty of watermakers on the market, but what sort of capacity is best for you? Experts say around 25 to 50 gallons of water per person per day is enough, you’re not going to drink that much water, certainly, or use nearly that much for showers and cooking, but an awful lot of water is used to wash down boats.

Of course, whatever the watermaker is used for, you’ve still got to figure out how often, and how long, you want to operate it. If you use, 30 gallons per day and you want to desalinate for three hours every day, you’ll need a 10 gallon-per-hour watermaker, or 240 gallons per day, to keep the tanks topped up. But a 400-gallons-per-day model, making 16 gallons per hour, will let you desalinate every other day for just less than four hours. It’s a balancing act.

Yacht watermaker misconceptions

When considering a watermaker for a smaller vessel, a complete picture is needed. There are some common myths which need to be dispelled before a fair decision on purchasing one can be made.

Myth 1: Watermakers are an expensive piece of equipment

It's true that a yacht watermaker may not be an essential piece of kit on a smaller vessel, but it is still an investment that must be thought about. (A very basic water model today costs somewhere upwards of £1500 for a yacht up to 20m and yachts over 30m start at around £14,000)

The cost of a watermaker is just as relative as GPS, radar, fenders, interior design, etc…, and just like this other equipment it offers convenience, flexibility and peace of mind.

Myth 2: Maintaining a watermaker is difficult and costly

A watermaker  needs little maintenance and is much less of a drain on time and money then first considered.

watermaker membranes are probably the most expensive part to purchase, but just like everything else if looked after from the beginning and routinely flushed and then pickled, so the need to replace the membrane will become less frequent. Prevention is the key with watermakers, if you maintain them properly, they require little investment.

See a guide on watermaker maintenance here

Myth 3: Pickling a watermaker is complicated

Pickling is the process of preparing a watermaker for storage if it will not be used for a period of time. There seems to be an overwhelming misconception in the boating industry that this is a complicated process.

Firstly, it is not. Simply put, pickling is storing a watermaker. The only difference is that flushing the system with a solution is needed to prevent the growth of bacteria. That's it.

When the watermaker is needed again, just discard the product water for the first 15 - 20 minutes to be sure the solution has been completely rinsed from the system.

Myth 4: A lot of power is needed

As mentioned previously powering a watermaker can be done using a variety of methods (electricity from the battery bank, an engine, or an AC generator.) Most watermakers are engine-driven, in which case battery power isn’t getting used. If a motor boat is owned, the engine will be used all the time. If a sailboat is owned, the engine will be used regularly to accommodate for no wind. If the engine is going to be run anyway, why not use the energy to fill water tanks?

Battery-powered watermakers do consume a lot of power and sacrifices may have to be made when deciding on what to use fresh water for. However, Fabienne Guerin from Reya SAS, experts in electricity production and conversion commented, "Batteries have developed over the years allowing new opportunities for superyachts, commercial boats and offshore vessels. 

Having exposed these myths around yacht watermakers, hopefully a fully informed decision can be made on whether or not one would suit your boat or superyacht.

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Discover more tips and tricks on how to maintain clean water on board, or find water treatment businesses on our online directory.