Only China Mieville could create a weird future where the earth is covered by oceans not of water, but of railways. Later in the book you learn that capitalist railway barons have created this weird future as their monopolistic power overwhelms society. SF nerds of a particular bent might recall Douglas Adams and his planet which became dominated completely by the manufacturing of shoes.

But "Railsea" is not a humorous book like H2G2, it's a rollicking adventure. The unreal, impossible setting becomes compelling and believable. In fact it's the most fun I've had reading any of his books. He didn't quite nail YA in "Un Lun Dun", but he gets it right here.