I think there is a misconception between using water to advantage and rationing. Recieving a tiny sip of water and immediately blooming like a flower is good cinema, But hardly realistic.Then again,how many people are found dead of dehydration with water in their canteens, obviously rationed? The level of physical activity and shelter can also effect loss. I was taught the best canteen was my own stomach. A dehydrated person rapidly loses coordination and mental clarity. I'd rather "fill up" and then secure water supplies ( if possible) while my faculties enabled me to do so. The online news services just yesterday posted an authoritie's refutation of the 8 glasses a day regimen with some interesting information. I'm still drinking my 8, it's 100+ here ;O)