Factual error: After the Missouri knocks the shield down, the admiral orders all aircraft launched, but the flight deck is shown in sailing transport mode, not flight readiness. Would have taken an hour or more to clear the deck and launch.
Factual error: How does the main hero Lieutenant Alex Hopper even get into the Navy as an officer in the first place with a felony breaking and entering on his record? You need at least a Secret clearance and a good moral background to commission as an officer, neither of which would be something Alex can get with a felony on his record.
Factual error: By the time the survivors of the JPJ arrive on board the USS Missouri, there are less than 3 hours before the satellite is in position. When lighting off cold boilers, it takes longer than that to get steam up, yet within minutes the bridge is informed that they have steam in all 8 boilers. If it was that easy, all the battleships at Pearl Harbor on December 7th 1941 could have gotten underway immediately.
Factual error: When the alien ship crashes into Hong Kong's Bank of China building, flaming debris can be seen flying past the statue of the Big Buddha, which was also established in an earlier shot as being located just behind the financial area of the city, Central. In reality, the Big Buddha is nowhere NEAR Central, out of view of the Peak, and not even located on Hong Kong island - but on Lantau island, to the west. The Big Buddha is also not included in the Hong Kong city skyline.
Factual error: Throughout the movie, Hopper is wearing both the silver and gold ESWS (Enlisted Surface Warfare Specialist) and SWO (Surface Warfare Officer) pins on his uniform at the same time. While it is possible to qualify both of these (one while enlisted, and the other after becoming an officer) you would never wear both of them at the same time. The officer's pin supersedes the silver pin.
Factual error: The USS Missouri is a 68-year-old museum ship. Only a few museum ships are still able to sail under their own power. The USS Missouri, however, is not one of them, and could never have left port. There is no fuel on board, corrosion has done serious damage to the rotor blades and controls, and if one was to try and refire the boilers, they would surely explode. Also, there is no ammunition on board, plus all controls have been stripped, and all tubes and barrels blocked to prevent dirt from damaging them. Therefore, it cannot ever fire a shot again. Though it was renovated in 2010, it was mostly to prevent it from rusting away and sinking.
Factual error: In the scene where the alien is in the engine room, it shows the alien scan an exposed gas turbine engine. The gas turbine engines on a US Navy ship are not exposed, they're encased inside a module (big steel box) so in the event of a fire they can be easily contained with HALON.
Factual error: Each turret on an Iowa-class battleship required a crew of 94 to load and fire two salvos a minute. The makeshift crew, including former Missouri sailors (mostly septuagenarians) were equaling that rate of fire with a half dozen men.
Factual error: During the ITV News "UFO Landing Confirmed" breaking news scene, the lower caption shows the text "Amateur footage confirms rumors". ITV News is a British news network and would spell 'rumors' as 'rumours'.
Factual error: Loading the projectiles and powder in the 16 inch rifles is done using a ram. The projectiles seem to just glide in on their own.
Factual error: There is a shot depicting the crew physically carrying a large shell from the rear turret of the Missouri to one of the forward turrets. That shell is supposed to be a 16" High Explosive shell which is also the lightest shell fired by the main battery. Those shells were roughly 5 feet in length and weighed 1,900 pounds and yet we see one being shoulder-carried by 6 men. They are also not utilizing the equipment designed for the purpose of moving these shells.
Factual error: Albeit needed cinematically, the satellite station is not projecting beams of light, they are transmitting sound.
Factual error: When Hopper orders to drop the port anchor during the final battle, the chain changes between being stretched and taut from scene to scene.