Factual error: An underwater scooter explodes like dynamite, collapsing the tunnel early in the movie, but underwater scooters are electric and designed not to kill divers. (00:29:12)
Factual error: When they go into the water, they put mouthpieces in, but, a few times, they talk to each other, which is impossible with mouthpieces in.
Factual error: The dive crew says they are using rebreathers as dive gear. Rebreathers do not produce bubbles, but most of the underwater shots show the team making bubbles.
Suggested correction: Sorry to burst your bubble here but there is scuba equipment which allows for talking whilst using a regulator.
They're not wearing such equipment. In the movie they're just wearing regular mouthpieces.
In the DVD commentary the writers explain that the divers should have been wearing full face masks which allow for communication, but the director changed it for mouthpieces, but kept the talking in. They pointed out this mistake.