Corrected entry: As they are pulling the girl onto the hull of the capsized boat in the ocean you can see trees and what looks like a crane boom in the lower left hand corner of the screen. (01:10:55)
Corrected entry: Black smoker hydrothermal vents are generally found in areas where the sea floor is spreading, opening fissures. Would not be found in subduction zones as in the Marianas Trench where crust is being destroyed.
Correction: The Marianas Trench Marine National Monument (protecting over 95,000 square miles of marine ecosystems) was established in 2009 after some 20 hydrothermal vents and associated exotic marine habitats were discovered in this subduction zone. Even more hydrothermal vents have been discovered in the Marianas Trench since then. The fact is, deep-sea hydrothermal vents (such as "black smokers" and "white smokers") can be found anywhere there is volcanic activity, including subduction zones. In fact, footage has been captured of black smoker hydrothermal vents in the Marianas Trench as recently as 2017. http://earth-chronicles.com/science/new-footage-from-the-mariana-trench-black-smokers.html.
Corrected entry: At the end, the ship has exploded after the crash of the helicopter and the crew is in the water. The woman is picking up the people from the water in her surfaced sub. How is this thing propelled if both forward thrusters are above water?
Correction: Why wouldn't they be moving forward? It would work on the same principle as a fan boat. We have no idea how powerful these thrusters are so can't say they wouldn't work if they aren't submerged.
Correction: If you look closely, you can see that's actually part of the keel fins along the hull.