Water is the most common substance found on earth.
The only water we will ever have is what we have right now. A person can survive without food for more than 30 days, but less than a week without water. A gallon of water weighs 8.34 pounds. For every 2.31 feet that water is raised above the earth's surface it can create one pound per square inch of pressure. For every 2.31 feet you are submerged below a body of water's surface there is 1 pound per square inch of pressure equally placed on your body.