A Boat application??
http://www.wind-sun.com/smf/index.php?topic=973.0
http://www.air-n-water.com/product/AF-330.html
http://www.air-n-water.com/product/AF-320.html
http://www.air-n-water.com/faq_swamp.htm
"Read how do swamp coolers work.
An evaporative cooler produces effective cooling by combining a
natural process - water evaporation - with a simple, reliable
air-moving system. Fresh air is pulled through moist pads where it is
cooled by evaporation and circulated through a house or room by a fan.
As this happens, the temperature of the air in the air stream can be
lowered by as much as 20 degrees."