If the planet was instantly depleted of all forms of water there would be nothing but geological formations, structures, bones, horns, and dust. As most organisms are composed mostly of water, the complete absence of it would turn bodies into their base structures, which would be certain to have no resemblance with what is current. It would be an ugly and barren world, and that is just at the immediate removal.
Without the weight of water in the ocean depressing the tectonic plates at the edges there would be a sudden surge of geological activity the world over. In the rush to find equilibrium, the magma and other gases confined to the underground would rupture free. The sudden surge to the surface would result in the formation of an ocean of fire in place of the water. Earthquakes and volcanic activity would overwhelm the land portions as the plates are thrown off balance. The atmosphere would choke from ash and harsh gas and throw the planet into an age of darkness.
It is uncertain how long shifts in plate movements and change would occur, but when after millions of years it would end, the planet would look nothing like its former self. No blue and green, it would be a planet of browns and reds. If there were an atmosphere after everything, it would be a suffocating and dry one reigning over a planet that is a configuration of ridges, mountains, desserts, and plains. It would be a barren and depressing world. It would be a planet devoid of any hope of life, but left with fragments of the life that had once existed, now frozen into the landscape as false fossils of a time forgotten.
However, if water was allowed on the world again, it would be by slow chemical formation or meteorite deposit. It is doubtful the beauty of the planet would ever return to its former splendor, but life may have a chance so long as the heat was present in the shallow pools that would lead to the chemical reactions that create the replicating molecules that mimic life. And from there the process would begin all over, on the water barren and in hospitable desert world once known as Earth.
Would a blue atmosphere ever return? It is possible, but surely unlikely. Should the planet recover to any great lengths, the sun would not be as forgiving in its life cycle. It seems that just when life would have the best opportunity to recover, the sun would begin its older age and cover the planet and its moon in its fire and end everything.
