Factual error: The sniper that lets Ice Cube roam free the roof all cat-like tries to make up for his mistake by shooting him repeatedly as he boards the heli. Which is nothing short of miraculous, since he's doing it with a Remington 700PSS bolt action rifle, in his capable hands suddenly turning into semiauto. (00:13:00)
Factual error: Talking about Darius Stone's military record, Agent Meadows mentions in passing that he holds the Navy record for highest dive at 250 feet. That wouldn't be the Navy record, that would be the world record, higher than the current one by over 50 feet. It's fine for a movie to make up some facts, obviously, but here they downplay what appears to be a next to superhuman ability. It's like having the main character running the 100 meters dash in 8 seconds and call it a "navy record." (00:25:50)
Factual error: Stone sneaks aboard the USS Independence (CVA-62) to investigate the bad guy's arms cache..yet, when he dives into the water, he is jumping off the USS Hornet (CVS-12). (00:50:35 - 00:57:45)
Factual error: XXX took a hit in his M2 Bradley and to get out of the predicament he rams the other tank, muscling it off its way and into the wall with crushing force. You don't need to look the tank specs up to see that something is wrong there, because tanks are fairly grounded vehicles not easily shaken off, and one looks much much smaller than the other; in fact the M2 Bradley is bit less than 30 tons and the bad guys' Abrams is around 60 tons. With this kind of disparity, not even Ice Cube's bulk can make the difference. (00:56:00)
Factual error: The way Darius hooks the APC up to the steam catapult wouldn't work. He apparently raises an arm of the catapult and attaches it to the APC, in reality however the arm is on the front landing gear of the fighter jets and the catapult is more like a small sled. (00:57:10)
Factual error: In this movie, it's the Secretary of Defense who picks the security detail for the President, but it's of course the Secret Service who does so, which is in no way in the same chain of command. (01:00:00)
Factual error: The Cobra is doing about 160-170 when XXX jumps onto the tracks. At that speed, any sort of erratic movement would cause the complete loss of control, even without jumping tracks to get airborne. (01:24:20)
Factual error: The main character manages to save the Prez thanks to a blatantly absurd trick; he gets (just like that, on the fly, at 160 mp/h bumping everywhere like in a pinball) his car on the railroad tracks, and rides them completely consuming the tyres, and going just on rims he actually attains a better peak velocity. Assuming the Cobra has exactly the same width as the train, this is not how cars and their wheels work. (01:24:20)
Factual error: The train conductor tells the bad guy that "air brakes are blown, can't slow us down anymore." But air brakes in modern trains are fail-safe; if they are 'blown', they lose pressure and therefore activate automatically. (01:27:50)
Factual error: It's been proven that when falling fast towards water, breaking the surface tension makes no difference in it's "softness", yet XXX is fine when he falls into the water after shooting it. If he fell for 5 seconds he would be going 60-70 mph and would certainly be injured or killed upon impact.
Factual error: From the title itself it should be clear that the movie is set when the President is giving the State of the Union address, which is in the middle of winter (end of Jan, approx). The movie has been shot between June and October, and it shows, since everywhere in Virginia the trees and lawns are in full green and people wear for the most part light clothes.
Answer: To break the surface of the water making an easier penetration. Hitting water at high speeds can be like hitting concrete. By stirring up the water it "softens" the impact.
EMTurbo