I'm trying to remember a book I read a while ago.
A lot of it was focused on zeppelins, that use a gas with a really specific smell you could detect easily (was it strawberry ? or blueberry?). The main protagonist is a boy, he's aboard a big luxury zeppelin that crashes on an island, maybe due to a storm, and can't go back because the envelope has lost gas.
There's also something about going on very high altitude with a zeppelin, so high that is almost non-breathable, and everything freezes. At that altitude, the protagonist(s) find a abandoned zeppelin, populated by some octopus-like creatures, which can deliver an electric shock with their tentacles.
I would say the book would be from the mid 2000's, when I read it, and for me it looked like a pretty recent book at the time.