Revealing mistake: As soon as the three survivors are coming out of the lab through the hatch underwater, they all signal each other to rise to the top. Look at Saffron Burrows, her cheeks are full of air and you can almost see the surface above her head. You can also see the exact same shot when she is about to be eaten by the last shark. And what's with that hand gesture - to cut or for the shark to stop? (01:26:30 - 01:33:10)
Suggested correction: Her cheeks are like that because when we all take in a big breath of air and hold it so not to breathe, that's what happens. The hand gestures when she goes in the water is so the blood can mix with the water so the shark can smell it.
The hand gesture the entry is referring to is just before she is eaten by the shark, the actress waves her hand across her neck area, allegedly to indicate to the director that she was running out of air.
I think she is giving the shark a sign... like stop or don't attack or something like that. So I think she is giving the shark a sign because right after she does that the shark stops swimming towards her.
Maybe in the context of the film you could argue that, but for scenes in which actors are performing underwater, they use that gesture to let the director know they are running out of air.
If you look EXTREMELY closely in one shot with the girl at a close distance and the shark far away you can tell the girl is actually computer animated. So I think she is giving the shark a sign cuz right after she does that the shark stops swimming towards her. But I could be wrong... that's just what I think.
