Definitely the American cover. It's really gritty and creepy, I especially love the kind of sonar effect relating to the EMP in the story. This cover has everything to do with the book itself. I find the Aussie cover very generic and misleading. It's basically too pretty. The Aussie cover has nothing to do with the story.
Hmm, I like the Australian cover tho. If she was changed by the EMP blast, it's not readily manifesting. It's making me wonder if it did something to her and what it's impact. :)
I really like the Australian cover. The American cover creeps me out too much to even want to read the book.
I don't like the American cover, it's way too creepy looking and looks like a cheap, C-Grade horror movie cover! I also love the sepia tone of the Aussie cover :)