At this point most people would realize that the water at that moment has more value than the heavy metal coins. Think about the critical needs of our body to stay alive. A person can go without air for only a few minutes. Next we need water. Depending on the environment, we can typically go without water for up to about three days before we die of dehydration.
People can go without food for up to about three weeks.
The point being, water is more important to our ability to stay alive than food. Recent flooding has emphasized the need to be able to individually purify water. During some of this flooding the local water treatment plants have been overrun, causing the utility water to become contaminated. There are several ways to purify water, including boiling and the use of chemicals, but having a good water filter available is probably the best and easiest way to obtain potable water. Katadyn, made in Switzerland, has been the standard in water filters for many years.