Continuity mistake: In the opening credits, there are eleven skiers in the pyramid. However when they fall in the water, and then all get up and ski off again, there are only ten skiers now. (00:02:00)
Visible crew/equipment: In the opening credits we see shots of water skiers climbing on top of each other to try and form a human pyramid. In one long shot you can see the side of the wake which the crew's speedboat is making. (00:02:35)
Continuity mistake: At the beginning of the movie with the scene of the water skiers, the amount of boats on the water goes from hardly any, to suddenly being loads. (00:02:35 - 00:03:40)
Continuity mistake: In the beginning when the water skiers are practicing, in one shot they are skiing right next to land and trees, in the next shot they are way out in the ocean near the ports. (00:03:25)
Continuity mistake: When two divers emerge from the water, one pulls their goggles up onto their forehead and the other pulls his goggles down to round his neck. Then the divers and Mike start talking about 'no overtime', and between shots the goggles around the divers neck vanish. (00:07:30)
Continuity mistake: When Dan walks down to a podium and looks over to see the dolphin knocking at the gate, the tee-shirt he is wearing changes from being plain white with a tag badge on his left, to a white shirt with a large blue stripe across it, with a tag badge being on the right. (00:08:20)
Continuity mistake: In the breakfast scene with Mike and Sean, the angle of the Tropicana juice carton keeps changing. (00:26:10)
Continuity mistake: In the breakfast scene, as Mike walks over to the table with the pot of coffee, the amount in the pot changes from barely full to almost full to the top as he sits down. (00:26:35)
Continuity mistake: In the kitchen scene when Mike and Sean are eating breakfast, the phone cord hanging behind Mike keeps changing from being loose and free, to all twisted and tangled. (00:26:40)
Continuity mistake: When Mike answers the call from Calvin the phone cord goes over his shoulder. When it cuts it's gone. (00:27:10)
Revealing mistake: As Mike and Kathryn are underwater with the submarine, they pass the control room, and in the next shot, as the submarine turns around, the front of it suddenly goes transparent. (00:32:00)
Visible crew/equipment: When Mike fires the harpoon at the shark, the wire the arrow is attached to is visible. (00:45:05)
Visible crew/equipment: After Calvin Bouchard makes the announcement to tourists visiting the Undersea Kingdom to evacuate, we see the tour guide lead the crowd through the tunnels. The green screen backdrop is still in the final cut. They forgot to add in the underwater effect.
Factual error: When the shark swims towards the glass, it doesn't move its tail. Sharks have to swing their tail in order to swim. There is no way this shark could be moving.
Factual error: The window in the underwater control room has to be made from some thick material such as plexiglas to stand the pressure. Yet the shark simply lifts its snout a little and sends thin pieces of glass shattering everywhere.
Factual error: When the shark is chasing Mike and his girlfriend near the end you can see air bubbles coming out of the fin (obviously a hole in the puppet). Real sharks do not blow bubbles from their fins.
Revealing mistake: The shark attacks a little wooden platform in the water which 3 men then fall through. You can see this is made from a lightweight wood such as balsa so that it will break apart easily, and it's not the sort of wood such a thing should be made of.
Factual error: Sharks can't roar - they don't have vocal cords.
Factual error: At the end of the movie, the shark broke through the glass. When the entire room was flooded, the shark grabbed someone and started chewing them. Sharks don't chew their food. If their prey is too large to swallow whole, they rip it apart into smaller pieces.
Factual error: In the scene where they try to lure the shark, it eats that man. How is it possible to fit in a shark's mouth when only someone's leg did before? Also, if you look outside the shark's mouth, it isn't going anywhere, which is also impossible.
Chosen answer: For some unknown reason, it has never been possible to keep a great white shark in captivity for a long period of time. They stop eating and swimming. The longest period was less than half a year and that was in 2007. At the time period of this movie, the record was 11 days.