Water, Water Everywhere, but Not a Drop to Drink! Nearly three quarters of the Earth's surface is covered by a body of salt water known as the world ocean. More than 97% of all water on the Earth is found here. Yet, in times of drought, people find themselves in short supply of the precious resource known as water. Coastal communities can look out to the horizon at the big expanse of blue only to realize it is of little use for daily survival. Or is it? The Ocean is critical to our survival in many ways. It links every part of the globe together. The water of the ocean helps to circulate heat from the equator to the poles, it provides climate control for coastal areas, it plays a key role in our global weather and climate patterns, it is a source of food in the fish we eat, and it can even be a source of energy by harnessing tidal power.