Corrected entry: Several times in the film it is mentioned that the rig is on the ocean floor some seventeen hundred feet below the surface. Yet Lindsy swims without any protection from the wrecked submersible to the rig, and Bud and others swim from one module to another. The absolute maximum depth the unprotected human body can stand is less than six hundred feet, and that is in the case of superfit divers who spend years training for their record dives (and some die trying). At seventeen hundred feet the water pressure would crush an unprotected human being like a schnitzel.
Corrected entry: In the scene where Bud is about to sneak up on Coffey, it cuts to a part where one of the Seals is unloading a magazine that was in the assault rifle. Later, when Coffey jumps into Flatbed, Hippy tries to fire at Coffey with the assault rifle, but the safety is on. Then Catfish takes the gun and shoots bullets at Coffey. Didn't they unload the bullets from the magazine?
Corrected entry: The scene in which Lindsay drowns and must be revived using CPR and the defibrillator: the use of the defibrillator is entirely inaccurate. First of all, the body of the subject must be dry. Because an electric current always runs the path of least resistance, the use of a defibrillator on a body covered in water would only result in the current running over the outside of the body, bypassing its intended target, the heart. Secondly, with water covering the body, the floor, and several of the other crew members, there would be a high risk of electrocution for the members of the crew. Finally, even though One Night repeatedly says clear before using the defibrillator, Bud is obviously straddling Lindsay's body and never moves away. He would have been electrocuted each time the defibrillator was used. (02:01:55)
Corrected entry: During the scene after the water tentacle is discovered, the whole crew has a meeting. At this time, Coffee is cutting his right arm under the table. In the following scenes, his arm shows no signs of any cuts.
Corrected entry: Just before Bud descends to disarm the warhead Lindsey asks him why it's he who has to go. His response is, "if not me, then who?" The answer's obvious: the Navy SEAL right next to him who's been thoroughly trained in deep-sea diving with the special breathing liquid and who would certainly know more about disarming nuclear warheads than a commercial diver.
Corrected entry: When Bud gives Lindsay CPR, every time he gives her a breath, her cheeks puff out. When administering CPR, this is not supposed to happen. The air is supposed to go into the lungs, and the chest will rise and fall. This is how the rescuer knows that he or she is giving breaths correctly. If air is going only into the cheeks, the rescuer must reposition the victim's head and try again. (02:03:51)
Corrected entry: After the nuke is disarmed, Lindsey pleads with Virgil to drop his weights and ascend back to the rig. Not possible - at extreme depths the pressure is so intense that even oxygen bubbles will not rise to the surface, being compacted to a density as great or greater than the surrounding water (water cannot be compressed to a higher density, no matter how much pressure is exerted upon it). Dropping his weights would have no effect. (02:22:30)
Corrected entry: Why didn't everyone just use the two remaining mini-subs to escape up to the surface?
Corrected entry: Near the beginning there is a scene where they are launching a submersible with Lindsey and the seal team in it. Lindsey waits until the sub is dangling over the water then pulls a lever and the sub drops about 10 feet into the water with a big splash. Several problems: 1) Those subs are hugely expensive. They put them in the water very gently. 2) Those subs are so expensive that they don't risk having a release mechanism as depicted. They use a standard screw shackle to ring and would have to have a swimmer let them go. 3) Due to the buoyancy of the sub, falling that far to the water would give all passengers back injuries due to the sudden deceleration when the sub hits the water.
Corrected entry: During the scene where Bud is falling into the abyss to disarm the warhead, Hippy states that he's 12,000 ft below. Just a few seconds later, Catfish says he's now at 17,000 ft. There is no time in between the 12,000 and 17000 ft that makes you think it's been more than a few seconds of him falling. It's not possible for him to fall 5,000 ft in just a few seconds. If it were, then it would have taken Bud less than a minute to get to the warhead. Later, Hippy says that it took Bud 30 minutes to get down there. So it doesn't add up.
Corrected entry: When Lindsey and the Seals first descend to the rig, the Seals get off of the top of the submersible and walk across the sea floor to the rig. There is sediment on the surface they're walking on (as evidenced by the marks the nuke sub left) yet none of it is stirred up. Deep sea sediment is very very fine (small clay particles) and walking across it would create large clouds of sediment.
Corrected entry: When they are filling Bud's suit with the pink liquid and he panics, one of the seals says "we all breathed liquid for 9 months, his body will remember" or something like that. But this is incorrect. In the womb our lungs may well be filled with amniotic fluid but we don't use them to breathe at all, all the oxygen comes from the mothers bloodstream via the umbilical cord.
Corrected entry: When Coffey steals the sub to take the nuclear warhead down the trench the big bearded worker fires the Seal's submachine gun at the sub. When he does he holds the gun by the extended barrel that Coffey screwed onto it earlier. This extension a suppressor and has holes drilled all along the length of it. The holes allow gas to escape the barrel. That gas is extremely hot and would have burned the worker, but he doesn't even flinch.
Corrected entry: When Ed Harris and Mary Elisabeth Mastrantonio (MEM) are in the wrecked utility sub deciding who will drown and who will use the dive gear to swim back, they decide it will be MEM. Why do they then sit in the sub and wait for her to drown? Why not have her hold her breath and swim until she drowns and then she won't be dead as long and would not be as hard to revive her?