We need water. Our home planet is three quarters water, and most of our great civilizations used it to travel. We need to drink it to stay alive, and we use it for fun and relaxation. Many of our most popular sports involve water, and teaching a child to swim is a simple part of growing up in many cultures. I grew up on the water and my hometown counted on the Boundary Waters between Canada and America for our livelihood. And when we went to space we brought water with us or found it out there and tamed it into reservoirs or tanks for our use. It’s not a shocker that we store a lot of that water in swimming pools so everybody can enjoy it.