Revealing mistake: When the megalodon attacks the yacht the party goers jump off the yacht, and some of them reach the large round safety raft. To the raft's right, there is a visible yellow line attached to it so it doesn't drift away for the shots.
Continuity mistake: During one scene, in numerous shots Ben pushes the throttle lever all the way up, but in shots between he never actually pulls the lever down.
Factual error: In different scenes, with the mama Megalodon, the teeth shown are around the size of the people themselves. In actuality, the Megalodon's tooth is only a bit larger than the size of your hand.
Revealing mistake: When the megalodon appears, Ben shoots a flare into the sky, which catches the attention of Hector who is flying in the chopper. In the exterior shot of Hector's reaction, there is a reflection of a fence on the side of the chopper, even though Ben signaled for help while out in the ocean.
Factual error: At the start of the film, a shark is attacking and killing a diver who is presumably at a depth of 1,500 feet. However, the shots actually show a great white shark eating a diver on the water's surface.
Continuity mistake: When Ben takes the photograph of the shark tooth to have it analyzed, he hold the tooth as he uses his digital camera. The camera is not connected to his computer, but the picture appears anyway. Also, Ben's fingers are not holding the tooth and the photo doesn't have a background.
Visible crew/equipment: In the scene where the three main characters are all sitting at a table, the reflection of the cameraman is visible in the picture at the back of the room.
Factual error: When the lobster is caught off the coast of Mexico, at the start, it has large claws, such as found in Maine. "Spiny" lobsters, without claws, are found in Mexico.
Factual error: The megalodon tooth shown in the film is actually not from a megalodon. It seems to be related to the genus Isurus, the mako shark, or maybe the Cosmopolitodus, which most scientists identify as the ancestor of the great whites. The tooth doesn't have a v-shaped root, it is laterally compressed and lacks a scar and fine serrations.
Factual error: During quite a few underwater shots, there are no air bubbles coming from any of the divers' air tanks, which likely reveals that those shots were filmed somewhere else.
Factual error: Sharks are attracted to electrical fields, but fiber optic cables, such as the ones used underwater in the film, do not emit any electromagnetic radiation for the shark to actually be drawn to.
Continuity mistake: The request Ben submits to the bulletin board, to identify the shark tooth, is titled "Mystery Shark". Then when Cat finds it, its title is "Mistery Shark", but when she reads it in the close-up, the spelling is correct again.
Continuity mistake: When the woman is parasailing, then tries grab hold of the researcher's hand, in all the underwater shots the woman is underneath the parachute, and in all the shots above the water she's above it.
Continuity mistake: Throughout the film, the megalodon's size changes repeatedly.
Continuity mistake: Outside the Apex building, when the time appears on the screen, the time reads 5:00 AM, but in the next shot the clock above the window reads 10:30.
Continuity mistake: After the boat sinks, the shark opens its mouth to eat two floating men. Their heads have been pasted in the middle of the mouth footage, but their bodies have suddenly disappeared, together with the floating device they held onto. Furthermore, they don't shout, cry, move, or show any reaction whatsoever.