Island moving

[wooosmallville]

So if the island truly is moving like Eloise said, how did ben and the rest of the others travel back and forth on a sub? That doesn't seem to make sense to me and it might just be because I'm forgetting things..:confused:

[Tabularasa]

If you remember when Ben gave Michael the boat, he told him to follow exact coordinates. The same happened when Daniel gave Frank the coordinates to go back and forth via helicopter. I think if you follow and exact route, you'll be okay.