The universe is a really, mind-bogglingly huge place. Much of it is made up of vast tracts of space, and most of it is empty. It is therefor surprising to learn how much of it is water.
Water exists in one form or another in almost every system in the Galaxy.
One exception to this is the planet Flimwiggle, where a fairly short-sited ruler outlawed all fluids of any kind, complaining that he didn't like their attitude. The Flimwiggians, being a somewhat dim-witted, but tremendously loyal and industrious people set out to do their leader's bidding. They pumped water into huge, fortified bunkers miles beneath the surface of Flimwiggle, destroying the drilling equipment afterwards. They filled huge tanker-ships with the stuff, firing them into Flimwiggle's mauvy sun. They even filled byros with water, then left them lying around in the bottoms of drawers until they disappeared, as byros do.