With Marine Watermakers: Size Matters

I will be the first to stand up and say that I LOVE my job. Where else would I get to work from the lower salon of my sail boat from whereever I am and talk cruising and watermakers with friends and clients.  But I will also admit that my work schedule is more of a lifestyle than a Job.  The 7 day a week work schedule does sometimes wear me down.  Then an email comes in from a client and makes all the hard work, late night emails and Saturday client communications worth it!  Sure it may be considered bragging when you share a favorable client water maker email, but the truth is we all like to get a pat on the back from time to time to help keep us smiling at 11PM while working on a Friday night!


“I commend you for your commitment to your product and your customers.  I had intended on getting a 12 volt watermaker system until talking with you at the boat show. I have never regretted getting an AC system. Many friends run their 12 volt units for several hours to fill the tank, while monitoring/augmenting battery amps. That is a lot of wear on the components for a little water. One friend recently missed an outing with friends in the San Blas Islands because he had to stay aboard and run his 8 GPH DC watermaker for several hours to fill his tanks. We did a passage with them, and it seemed that the sound of the watermaker was nearly constant during daylight hours, while underway. I never run mine for more than an hour, getting the amps from the main engine, my Honda generator, or shore power.  I have made more than 1000 gallons of water so far, with only 37 hours of run time.”

Lane Scott
La Paz, Mexico
SV Adesso

Water Maker Hose Run Lengths



A benefit of a modular sailboat watermaker is that the individual water maker modules can be mounted as far apart or as close together on your boat as space dictates (I’m assuming you don’t have a 300ft Mega Yacht and want to spread the Modules from stern to bow).  A plumbing run of 10 feet between the modules will not have a negative effect on system performance.  We oversized the sea water boost pump to supply the high pressure pump, which makes sure your high pressure pump gets plenty of sea water flow.


All SeaMaker water makers come standard with 30ft of low pressure sea water inlet connection tubing, 30ft of low pressure brine discharge tubing and 30ft of low pressure fresh drinking water tubing.  For the high presure connections on the water maker, we provide a 3ft and 5ft high pressure hoses to connect high pressure pump to the RO membrane pressure vessel assembly and then to the remote panel.  Although we have found that most water maker installation can use these standard high pressure hose lenghts, we can supply two 30ft high pressure hoses without a loss in system performance.



Shipping a Water Maker

Water Maker Shipping Boxes


Before you install a water maker aboard your cruising boat, we first have to get it to you in one piece, which is where our custom made shipping boxes some into play.  David and Amy’s 30 gallon per hour water maker made it safely to Texas and you can see some of the unpacking photos on their Blog entitled Chasing Stars.They are in the process of outfitting their new  Helia 44 Cat made by Fountaine Pajot in La Rochelle, France.


The water maker ships in 4 boxes anywhere in the continental US for $285 using UPS Ground and for International orders we use DHL.  DHL Shipping costs obviously vary based on Country but Australia and Europe for example are both about $700.  The most expensive shipping cost we have had so far was $1200 to Tahiti!  A pallet of 3 water makers by contract to the Philiphines cost $1200 and took 28 days via sea freight.
The box sizes and weights for a 30 gallon per hour water maker are:
Box 1 Pump and Motor 25″x15″x14″ 54lbs
Box 2 RO Pressure Vessel Assembly 47″x13″x11 33lbs
Box 3 Prefilters, Boost pump, and all Misc hoses and fittings 18″x12″x16″ 33lbs
Box 4: Remote Panel 14″x10″x10″ 5lbs
Optional Box 5: Consumable Cruising Kit 14″x10″x10″ 14lbs


I’m knocking on my wooden desk aboard SV THIRD DAY when I type this, but so far we have shipped hundres of water makers without having one “lost in the mail”!

Water Maker Safe TDS Levels

Question: What is the safe Water Maker TDS Levels for drinking water?
Answer: 500ppm (parts per million)
Now for some details: First, TDS stands for Total Dissolved Solids and when dealing with sea water RO, the TDS level is mainly composed of sodium and chloride ions.  A new RO membrane should start producing 100-150PPM water and then slowly climb until it reaches 500ppm and it’s time for a new membrane.  While out cruising I would constantly meet cruisers that didn’t have a TDS meter to check their water and were relying on how it tastes.  After their plants started dying and their cat wouldn’t drink the water, one of our friends bought a TDS meter and found out that they were drinking 1500 ppm water….yikes.  Don’t rely on the taste test becuase the TDS can start hurting your kidneys before you can “taste” the salt and at $25 for a good TDS meter, it’s a must have on a cruising boat.

Facts About Marine Water Maker RO Membranes

Marine Water Makers have a reputation of being expensive to maintain.  That can be true for water makers that insist on using proprietary consumable parts such as RO Membranes.  However, an off the shelf 40″ long by 2.5″ diameter RO Membrane made by Dow Chemical costs $187 and is the gold standard for quality and salt rejection the world over.  Unfortunately, rather than using this industry standard membrane to help keep future operational and maintenance costs down, some water maker companies have “special size” RO membranes made which can only be bought from the Company for $699.  Other water maker companies don’t go as far to have special size membranes made to lock you in, rather they simply say that their membranes are “special, super, high rejection, or magic” and then charge $499 for the same $187 membrane.  In your water maker shopping process, be sure to ask about the brand and replacement cost of the RO Membrane.  If they won’t tell you, run.  If they blow smoke at you and try to call it “special” to justify the $500 cost, run.


There are two great videos on our website that show how RO Membranes work and how they are made.

Custom 60GPH Water Maker in Genoa Bay Marina BC Canada


How large a water maker do you need?

For most cruising boats our most popular selling water maker is the 30 gallon per hour unit, but the Genoa Bay Marina in BC Canada needed a larger unit. To save on shipping costs, we sold them the 3 major components (Pump/Motor, Pressure Vessels/Membrane Assembly, and the Remote Panel) and then worked with them to design and build the water maker using locally available parts. If only cruising boats had this type of room for the installation 90% of the difficulty in installing a water maker would vanish.

Seattle Boat Show Water Maker Overview



Seattle Boat Show Water Maker Overview Video


This short water maker overview was filmed while in our booth at the Seattle Boat Show in 2012.