Nimbus: A Steampunk novel by B.J. Keeton and Austin King

What a terrific new world these authors have created. A world where humans have been forced to live on islands in the sky in order to escape a deadly cloud of corrosive gas that covers the surface of the Earth. Trade is done via airship and precious water needs to be harvested from storm clouds. There is a pretty exciting adventure story in here too. The novel also features strong characterisation, easily overlooked in steam punk / fantasy novels but so important for hooking you into the story and the world. A word of advice though - I didn't really like the prologue, I felt it was weak and out of character with the rest of the book. Just keep reading it gets much better as you go on.