T&T: Aqua Whisper Watermaker Boost Pump

[m/v MOJO]

Not sure how useful you will find a watermaker on the ICW - water is readily
available making it not really worth the trouble of running and maintaining a
watermaker.  Additionally, since you will find many sections with brackish or
even fresh water, you will have to be careful to adjust your membrane pressure
so as not to exceed the rated output of your system.  i.e., if your membrane
is rated at 20 gph, in fresh water at the same input pressure  you might see
30+ gpm of product water.  Don't take this as a bonus, something for nothing!
Instead, lower your membrane water pressure from 800 psi down until your flow
of fresh water drops to 20 gph.  (I've gotten good production with pressures
as low as 200 psi in brackish water.)  Otherwise, you will significantly
shorten the life of your membrane.

In terms of a boost pump, if you use the watermaker while underway, you might
consider using the main engine's raw water cooling pump as a boost pump.  Just
put a tee in the line after the output of the raw water pump and let some of
the cooling water flow to the watermaker.  You can route the brine output of
the watermaker back into the cooling loop via another tee if you want, or you
can just send it overboard.  Don't worry too much about flow regulation.  It's
rare to find a raw water cooling pump that doesn't have much higher flow than
the engine needs to keep it cool.  Siphoning a few gallons per minute off the
pump to supply the watermaker most likely won't be noticed by the engine.  I
ran an 80hp Lehman with an engine driven watermaker pump for 6 years using the
original engine cooling pump to supply the watermaker feed water.  The brine
was discharged overboard. Made for a very simple and reliable system, and I
never had any hint of engine overheating.

Ray B
m/v MOJO
Beebe 49-10 Passagemaker in Steel
www.mvmojo.com