Great American III carries a limited amount of drinking water on board, so Rich uses a Katadyn POWERSURVIVOR 40-E desalinator to replenish his water supply. A desalinator is a piece of equipment that makes fresh water from salt water. The way the desalinaotor works is simple in principle, although complex on the molecular level. The salt water goes into the desalinator and is pressurized by the motor. The salt water is forced through what is called a “semi-permeable” membrane (water molecules can pass through but not salt molecules), and fresh water comes out the output. In a simplified (although not completely accurate) way, the salt is filtered out of the water.