Corrected entry: Sea World Orlando is (obviously, since it's in Orlando) not connected to the ocean, as suggested in the movie. Therefore, there is no way that the shark could have just made its way into the park.
Corrected entry: The 'Underwater Kingdom' of Sea World Orlando is actually an attraction called Terrors of the Deep. The tunnel shown in the movie is NOT part of the actual lagoon of the marine life park, as is suggested in the movie.
Corrected entry: The shark swallows the unfortunate British cameraman that gets trapped in the tunnel with it. Later, after breaking the Plexiglass wall, it chews up and swallows some random guy. Almost immediately afterwards, as Mike and Kay scramble around, the shark opens its mouth and we can see the body of the British cameraman, with the convenient grenade in his hand. How could the British guy's body be in the shark's mouth after it's eaten the second guy?
Corrected entry: When the shark has chased Mike and Catherine they get back into the space where they go in and out to the water. The room is completely filled with water. We see Mike's hands turning the vent-things (I don't know the proper words for them) to let the water out, only problem is his hands are not IN water. They are in air, not a drop of water in sight. Then we see the room emptying of water and Mike and Catherine are both still in water. Mike's hands should have been underwater in every shot of the scene up until then. It's obvious that the hands were Mike's as you could see his wet suit.
Corrected entry: At the very beginning of the movie, there is a severed fish head just hanging there in the water. It is blatantly obvious that the fish is alive because the mouth is in obvious motion.