Revealing mistake: At the end of the movie when they reach the surface, you can see that the horizon is nothing but a big wall with the sky painted on it. You can see the water splashing up against the wall.
Continuity mistake: After the shock waves, Snyder says he has a 'fire over here.' You see Scarpelli putting out the fire with a fire extinguisher. The hose is attached to the extinguisher, but a short time later she is holding the hose in her hand, then in the background a short time later you can see her, and the hose is again attached to the extinguisher.
Factual error: An animal that lives in the deep sea cannot live in the open air above the water.
