Plot hole: Considering the incredibly elaborate plans Maddy makes to have her husband murdered after forging a will she knows is invalid so he dies intestate and she - as his widow - gets his entire fortune, you'd think she would have worked out one little fact - Edmund Walker does not die intestate. It is established in the film that the dud will supposedly written by Ned Racine replaces a previous, valid will which bequeaths half his fortune to his niece Heather. When the new will is declared invalid under Florida law the previous will takes precedence and Heather and Maddy split the fortune. In no way will Maddy get the lot.
Plot hole: After the first attack on the U96 the captain decides to resurface after sunset. However when they do resurface it's broad daylight.
