Factual error: 1. Why wasn't Prairie/Masker operating all the time they knew a sub was out there? That's SOP for the US Navy. 2. Spearfish torpedoes are homing torpedoes. They wouldn't just shoot by on each side of the ship, but if they did, they'd turn around and pursue their target until they ran out of fuel. 3. Why didn't the ship employ countermeasures when the sub launched torpedoes? A noisemaker, a nixie - Navy ships don't just cross their fingers and hope the torpedoes miss.
Factual error: Sean says he was the coxswain on HMS Achilles. However, in the previous episode's flashback to the beginning of the red flu outbreak when Achilles was still in operation he was shown wearing lieutenant's rank insignia. The coxswain is the senior rating aboard a Royal Navy submarine and holds the rank of chief petty officer or warrant officer; he is certainly not a commissioned officer.
Factual error: Dr Scott's official personnel record shows that she received her only medical degree, an MD, from Cambridge University. However, British universities do not award an MD as a first medical degree; in Britain, unlike the USA, this is a very prestigious (and rare) postgraduate research degree only awarded to very highly-qualified doctors. The medical qualification degree at Cambridge is an MBBChir (Bachelor of Medicine and Surgery), which is equivalent to an American MD. Although Americans expect doctors to have an MD, it is extremely unlikely that an official personnel record would give false information. The record also shows that her first degree was a BS in chemistry from Oxford. Oxford does not award a BSc degree (as they are called in Britain); most of its undergraduate degrees, even in science, are BAs.
Factual error: Ruskov introduces himself as a vice-admiral. However, he wears the sleeve insignia of an admiral of the fleet, two ranks higher: a wide stripe and four regular stripes (instead of the wide stripe and two regular stripes of a vice-admiral). On his epaulettes he wears the four stars worn by an admiral of the fleet until 1962, instead of the single large star of a modern admiral of the fleet or the two regular stars of a vice-admiral. Given Ruskov, it is inconceivable that he would reduce his own rank or wear the insignia of a higher rank but not use it.
Factual error: The ship sails up the Mississippi river to St Louis. It needs a minimum water depth of 31ft of water. The water depth at St Louis is approx 20ft, so it would run aground. The ship needs 55 meters to clear the mast. Interstate 255 bridge south of St Louis is a fixed bridge with only 27 meters of clearance above the river, so the ship could not pass. Note that New Orleans is the port for Ocean going ships with depths to 200 ft.
Factual error: After the nuclear detonation LT Alisha Granderson reports the ship's fuel reserves as 11% and states they will run out of fuel in less then 6 hours, even at maximum conservation. Working from published specifications (Wikipedia and www.globalsecurity.org) 11% should last them for more than 24 hours operating normally at 20 knots and one would think that maximum conservation extends this timeframe. (00:27:15)
Factual error: They have EOTech or similar holographic sights mounted on their rifles, but "scope in" with a night vision sniper rifle scope of some kind to take out the two targets. The EOTech holographic sights are not night vision, nor have the magnification and reticle that was used in the show. (00:17:50)
Factual error: When Chandler is looking through his rangefinder at the Italian passenger liner, the lat-long coordinates indicated in the lower left corner of the display are quickly decrementing, meaning they couldn't possibly indicate a current GPS location. In addition, the numbers are nowhere near the coordinates Chandler gives when he attempts to hail the passenger liner ("48° north, 15° west").
Factual error: "When we reach the States you will be charged with War Crimes and prosecuted to the full extent of the law." Despite a lot of assumptions, the USA is the only major power to have opted out of this convention. You cannot be charged with "War Crimes" in the USA. (00:05:55)
Factual error: The dead Royal Navy submarine captain wears a beret. British submarine captains still wear the traditional submarine captain's white-topped peaked cap if they wear headgear at all. His cap badge also features the king's crown, which has not been worn since George VI's death in 1952, instead of the current queen's crown.
Factual error: The Royal Australian Navy special forces operator Wolf Taylor is a 'senior chief'. There is no such rank as senior chief petty officer in the RAN. The two most senior non-commissioned ranks are chief petty officer and warrant officer (the latter a non-commissioned rank and not the same as an American WO).