Corrected entry: The shark follows Brody into the sunken ship (yeah, right) and eventually the chase ends with the shark at the end of a very narrow passageway, with no room for it swim further forward, and no room to turn. Since the rigid nature of a shark's pectoral fins means that they cannot swim backwards this one would be stuck. And since Great White sharks have to constantly swim in order to breathe, the movie really should have ended right there.
Corrected entry: During the scene on the banana boat, the woman who is attacked by the shark quite deliberately shoves her leg into the fake shark's mouth as it missed her when it came up out of the water.
Corrected entry: When the shark comes near Michael's scientist friend under water, it doesn't attack him. A few shots later, the shark is biting the wood. It shows blood in the water. Where did the blood come from? No one got killed.