I'm not sure as to weather this question has been answered already, but why is The Island underwater, as seen at the beginning of Episode 1 Season 6?
I'm no nuclear physicist, but I'm pretty sure that a bomb blast, no matter how powerful, would cause The Island to sink. When you think about the actual size, and highest point, of The Island it would mean that the sea has risen, and quite considerably, in that part of the ocean. Surely a bomb blast would more likely destroy the DI village, wipe out all the jungle foliage and generally sear all the landscape rather than actually cause The Island to sink??
Like I said I don't know if this has already been discussed, or even if it is relevant to the actual story or was just done to look good 'for effect'. It's just bugged me since I saw it.