From what I understand how cities pump water, is they have a water tower full of water that a pump keeps full. The water in the tower goes through a series of pipes, getting smaller each time, producing force along with the gravitational force. I'm wondering if the same type of system could be designed for a water maker. Have a bag that's hooked to a small block on the shrowd. Lower the bag into the water and fill it up...pull the line and raise it up. Have a series of hoses that reduce in size on the way down to a filter. Could this be feastable or would the bag need to be so large that it wouldn't work on a sailboat? If it did, it would be a slow process but it would also not require any electricity or manual pumping. Ideas? Come to think of it...I'm sure it would work of the whole bag was just one big hose that got smaller on the way down. The smaller the hose gets, the more pressure builds. Ok...who's going to build it and patten it? All I ask is you give me one free 
