Actually you only need 800 PSI which is still way past what a ram pump can
produce. There is a tow behind RO watermaker called the Waterlog that uses
a small mechanical pump powered by a propellor. Though JAX claims them to
be mythical I met two cruisers in the BVI who used them all the way from
Gibralter and were very happy with their performance.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"joe_sailor" wrote in message
...
You *might* get 1 or two PSI from the ram action. You need about 3000!