Factual error: When Tina's Joy is rammed, the boat moves away while turning. The boat, given the rate it was turning at and angle of the wind, should have tacked (the sail should have swung to the other side), knocking Tina out, but when it cuts away and cuts back, the boat has mysteriously stopped turning, and not tacked. (01:10:15)
Factual error: The "Cable Junction" in the movie is a transformer junction station built on a rock pile however when you look at it there is no algae or barnacles anywhere on the rocks. This is impossible because algae and barnacles thrive on rocks in sea water.
Factual error: Whenever we see the shark gliding through the water, we only see the dorsal fin, never the tail fin. Realistically, we should see both fins above the water in at least some shots - especially when the dorsal fin is fully out of the water.
Factual error: Several times Chief Brody was seen to both transmit and hear the boat radio without him taking his finger off the mic button. If the button is pressed you can transmit, but not receive.
Factual error: Brody would have also received a shock inside his raft due to proximity and water continuity.