Several times, the sharks swim backwards to move down a different hallway or change direction. This is an impossible feat for sharks, regardless of their intelligence. [Trying to point out factual errors in a film like this is like saying its impossible for Dinosaurs to exist in "Jurrasic Park". Its commented in the film by the characters that they shouldn't be able to do that and yet somehow they have been able to.]

Near the end of the movie when the three are preparing to exit the sinking building and float to the surface the comment is made that putting the life jackets on will cause them to float to the surface too quickly and their lungs would pop.  When you watch them swim to the top, they actually swim faster than the jackets/fire extinguishers go. [The fire extinguishers and life jackets were rotating and because the fire extinguishers were going off, they would not go straight up. The force from the fire extinguishers would push the jackets down or at least slow them down when it was pointed upward, and since it was rotating it would most likely go up as slow as it did.]

Considering the huge size of the glass window in the facility and the fact that it is so far undersea, it must surely be several inches thick and therefore able to withstand an immense amount of pressure. Yet it breaks ridiculously easily when the shark rams the lightweight gurney into it from a considerable distance. If it was that easy to break, how come the sharks never tried it before themselves, especially as later in the movie they can knock out heavy steel doors without any effort at all?" [Firstly, I don't think the window breaks ridiculously easily. First it cracks and then big lumps of thick glass start popping out before it finally shatters. Secondly, the gurney, which is designed to be suspended from a helicopter so is probably very sturdy, is propelled at the window at great speed by the sharks who seem to have the express intention of causing the window to shatter. Thirdly, the sharks learn new tricks throughout the film. Maybe they didn't know they had the strength to break the window until they tried it. When they succeeded in breaking the window, they decided to have a go at bashing in steel doors, which seemed to take a lot of effort to break as they had no tools to do it with.]

Am I the only one bothered by Preacher getting bitten so badly he nearly passes out from the broken leg, yet when he is either shooting at the shark and Carter, or setting the wires, he stands easily on his injured leg? At first the leg seems to inhibit him, but it must magically heal as the movie continues. [It's possible that he was only bitten badly - it never says that his leg is broken. Also, if it was, he could have been balancing on his unbitten leg.]

In the scene where the remaining crew are climbing the maintenance shaft where the debris is falling from the elevator blocking the full way up, why doesn't the elevator itself fall? It's in a bad enough state as it is, so why does it not fall? [It may have become jammed in the shaft.]

All winches on choppers have an emergency release in case something like the shark grabbing it happened - why didn't they use it? [It was a rescue team. They would do anything to rescue Jim, and in this case things happened too fast, so the chopper was pulled without the crew being able to do anything about it. Also it would make the rescue team look bad if they just cut the wires and let Jim fall into the ocean. So I guess they stood up against a dilemma and weren't thinking straight.]

If the crew acknowledges the fact that these sharks have been modified enough to possibly swim backwards, why are they so shocked when it happens? [Only the lady doctor knew that the sharks had been genetically altered. Everyone else just thought that they were breeding them for the protein complex which would not neccessarily mean that they could swim backwards.]

They are searching for batteries for this real big flashlight and finally find some in the clock. 1. How can such small batteries provide enough energy for the flashlight? 2. How do they fit in? I'd say you need bigger batteries! [They don't. The batteries come from a varity of sources, the clock provides just one (maybe 2). That is why he is looking for a sex toy, for extra batteries.]

Doesn't anyone watch the Weather Channel? Why was this storm a surprise to anyone? At the very least, the pilot who flew Samuel Jackson to the site would have been made aware of it before he left the airport. Also, why would a facility of this size and type not have a full-time medical provider on-site if they were going to continue to perform experiments through the weekend? Stupid from start to finish. [The storm wasn't a suprise. What did the pilot care who flew Sam Jackson to the facility? That pilot was being paid by the hour for a quick turn around. The facility had sophisticated weather monitoring equipment (or at least a decent link up) as shown by many shots of the woman in the control tower who is watching the storm develop. She tells everyone in advance that there is a storm coming and they shut down the fuel pumps. The storm has no effect on the facility whatsoever, UNTIL it has been damaged by an exploding helicopter. Not stupid at all.]

Near the start of the movie during an underwater shot, we see a teddy bear sink like a lead weight when it would ordinarily float. [It may have a weighted base so that it always sits upright.]

Anyone notice the shark could break through a steel door in 4 or 5 hits that's made to withstand tons of water pressure, but it takes 6 or 7 direct hits to get through a chainlink fence at the end and never succeeds? [In the beginning it is mentioned that the chain link fence is made of titanium. Titanium has a higher tensile strength than steel. The thin chain links are in fact stronger than the steel hinges on the door. Another re-correction: the fence is made of steel - during the scene when the last 3 survivors were on the surface (after LL Cool J was rescued) the other guy says "son of a bitch, they were using us, the fence is titanium below, but it's just steel on the surface" or something like that. Therefore there is no good reason why the Shark couldn't get through the fence.] [The door the shark is trying to batter down already has tons of water pressure behind it, the shark's added attempts were more than they were designed to withstand.]

Near the end of the film when LL Cool J gets bitten by the shark around his waist why doesn't he get ripped in half like all the others did when the shark first got them? [If you remember when they are climbing up the maintanence ladder and carter is trying ot save Jan she gets caught by the shark around the middle but is not killed instantly.]

Didn't anyone think it strange that after initial shark attack that no one of the group wonders where Preach is or mentions him, yet they don't seem a bit surprised when he saves them all? [Actually, when they hear noises at one point earlier in the film, they call out "Preach?", so they know he might be around, but they probably assume he's dead - if the second floor was flooded they would assume the third floor was too.]

How did the sharks know that they could "sink" Aquatica? It was already underwater. Were they genetically enhanced and provided with blueprints on how to do this? The whole concept is flawed. Despite having enhanced intelligence, they would still have to learn that CCTV cameras transmit images to the cast. They could never know that wounding someone would bring a helicopter they could use to sink the structure. The whole concept of the film is based on the, frankly, wrong assumption that being more intelligent makes a creature automatically 'know' more stuff. Well it doesn't. It would just make them more able to learn and understand. So who taught them? [It's entirely possible that the sharks just got lucky. They could work out from seeing the blond guy making signals into the CCTV cameras that there was someone watching at the other end, they got very lucky with the helicopter (it was pure chance that the stretcher broke and dropped into the water) so it's possible that attacking Jim was just malicious and only when the stretcher fell into the water did the rest of the plan fall into place. It doesn't take any great amount of knowledge to realise that filling things with water sinks them. The mistake presumes that the sharks had every move planned - as the female scientist says, they're still just animals. Most of the events in the film are pure bad luck.]

The female lead says that when her father was suffering from Alzheimer's, she had to tell him every day that his wife was dead "and watch that knowledge hit him like a train wreck". If he had no memory, why make the poor man suffer like that? Why not just tell him she was down at the shops every time he asked where she was? [That is a moral dilemma. Obviously the character didn't want to lie to her father and thought it would be best if she just told him the truth. It would would also avoid further questions like "why is she taking so long down at the shops?"]

If these sharks were herding the people to the top of the structure to get them to flood it, why did they keep killing them off? If no one was left who would flood the building? [The sharks kept attacking to get the people moving.]

After the female doctor returns to her quarters and retrieves some papers, she is trapped on a table or a desk or something and she pulls out a wire that shocks and kills the shark. Isn't it convenient that the jolt ends right when the shark dies, even though the circuit would have stayed intact and she would have been shocked upon entering the water. [The entire reason she went through the whole revealing process of stripping out of her wetsuit was so she could use the rubber to avert the charge.]

Sharks don't make any sounds. [Actually, shark attack victims have been documented as saying that right before they were attacked, they heard a roaring sound, similar to a lion.]

In the beginning when the blonde-haired ex convict was in the tunnel surveying the sharks, the sharks co-ordinated an attack in which they both hit the tunnel in the same second. How could they have done this? Becoming smarter does not give them the ability to communicate. [No, but being smarter might allow one to observe the other's preparation to attack, predict the attack, and work in tandem in order to secure a piece of the kill. Intelligence advanced enough would allow them to follow a predictive logical process and act on their conclusions.]

The sharks cut the electricity for the lights when they were trying to catch Carter. However, when the helicopter comes Brenda is using a spotlight. [They probably could only attack the circuit to the underwater lights; in the surface shots when Whitlock is being loaded into the helicopter, lights are visible around the perimeter.]