The illustration above literally defines the Great Lakes region by water.  On a much larger scale from space even we only see our world as land or water.  Money, religion, ethnicity are imaginary boundaries placed on ourselves by the ideas of man.  Our planet divided into what is water and what is not.  With that idea in mind we are a planet that is not wholly unique and certainly not the only planet in existence to have water.  As a matter of fact , astronomers also categorize planets as water worlds and worlds without water. Making other solar systems and the planets therein defined by water.  The weather systems on our world are determined by water temperature and the surrounding air and how they interact.  What we eat and is so dependant on access to water, that the lack or abundance of it determines feast or famine.  On the microscopic level we, along with all other living creatures on earth are defined by water.  The living cells of all plants and animals are defined by water. What could be more important?