I don’t believe that the submarine was the actual way that The Others got on and off the island, I have no doubt that it worked, but I just don’t think it was the main way.
When Juliet came to the island, they required her to be sedated and strapped down. I don’t think this adds up. I submit that the submarine is all just for show, and there is some other, more mystical way that The Others get to and from the island.
For more info see my Original Post.
Wrong. The submarine is most definitely real. We’ve sen it in use a lot since I came up with this theory.