Understanding How a SW30-2540 RO Membrane Works

To understand how a boat water maker works, you first have to understand how a RO Membrane works.  This nice YouTube Video animation takes the mystery behind the membrane construction away.



Can I Run a Marine Water Maker in Fresh or Brackish Water?

Cruisers are not always floating in just sea water.

Sometimes they are in fresh water lakes, rivers or brackish waters but they still want and need water.  If you understand the process and limitations, then you can run your water maker in sea water, fresh water or brackish water.



Where Can I Run my Cruising Water Maker?

The short answer is if you you would swim in the water, then you can run your water maker there.

For a little more details, I put together this YouTube video on where you can and shouldn’t run your cruising boat water maker.


Sailboat Watermaker Installation on a Crealock 37

Small Sailboat Watermaker Installation

Hi Righ, here are several photos showing the installation of your water maker on Lagniappe, our Crealock 37.   I was concerned with where I could mount the various components but everything other than the control panel fit nicely in the engine room on the port and starboard bulkheads.

 System works great and served us well last season in the Bahamas. 

 Thanks for your support and guidance during the installation and commissioning. 


 Greg & LizAnn Mulvany

S/V Lagniappe

Crealock 37


Here are some photos of Greg’s installation. First I have to compliment Greg on having such a darn clean and nicely laid out aft engine compartment.  I’m sure it was fun to hold the motor up on the bulkhead for mounting, but what a great job of using “wasted space” to mount gear.  The installation highlights that you can mount the motor on a vertical bulkhead by rotating the pump on the motor 90-degs.

watermaker high pressure pump


From thhis angle you can really see how every inch of space was used for the water maker.

Watermaker on a small sailboat


Greg mounted the remote panel in the lazarette and this photo shows his 1/4″ red sample hose that is used to test the product water quality before sending the water to the tank.  If you look closely, you can see the white float in the flowmeter and the PSI pressure gauge is set to 800psi, so the unit is running.

water maker lazarette panel location


It may seem obvious when you see it, but I like this photo because it shows Greg using his product water sample line to easily refill his on-deck water jugs.   Our Hudson Force 50 carries 450 gallons of water, but we still keep a 5 gallon water jug on deck for emergencies or to share with our friends that don’t have a watermaker!

Marine watermaker filling a sailboat water jug





Tartan 37 Water Maker Installation

When I heard one of our water maker clients was making a stop over in Morro Bay, of course we had to have some cockpit drinks with them and snap a few photos of their SeaMaker 30 water maker installation.  I have to admit that Lewis on SV Eleutheria did an installation job that puts some professional boat yard installations to shame.  The happy crew is on their way to Mexico and their great use of space on their 37ft boat allowed them to install a 30 gallon per hour water maker without giving up much storage space.  They will be powering their water maker using the trusty Honda UE2000i generator and at $900 with free shipping over the internet  for the Honda, I wouldn’t want to go cruising without one!

Here’s a shot of the beautiful cruise ready boat on a Morro Bay mooring ball.


Where do put the control panel?  How about making use of some wasted space behind the campanion way ladder?

Small boat watermaker installation Tartan 37


The 5 and 20 micron prefilters and Valving and Cleaning assembly are both mounted on the starboard cockpit locker forward bulkhead.

Sailboat watermaker prefilters mounting location



The High Pressure pump and motor are mounted on a shelf in the starboard cockpit locker and you can see the RO Pressure Vessels mounted up high in the cockpit coaming.

Sailboat watermaker high pressure pump mounting location

A favorite mounting location of mine for the RO Pressure Vessels is tucked up in the cockpit coaming.  It’s typically wasted space so you don’t lose valuable storage space.  Notice how nicely Keith tabbed the fiberglass mounting feet of the pressure vessels right to the hull.  Nice and clean installation.

Sailboat water maker pressure vessels