"Aye, there's much. Especially since I'm supposing you thought that when you cast him overboard, weighted down by the cannon, that he was never to return. But did you ever ask yourself what happens to a man when he's stuck at the bottom of the ocean, cursed never to die, and there are forces in that selfsame ocean greater than even the Aztec mages?" No, Gibbs really doesn't think that he can either scare Barbossa or make him feel guilty. But just the telling of the tale to the traitor will make Gibbs feel better.