Towards the end of the movie, Commander Lynch swims back to the ship, once on board her clothes and hair are dry, and no wet marks where she boarded the vessel. The same when she returns to the life boat.
Commander Lynch is not a United States Naval Commander based upon the insignia upon her collars. She should be wearing oak leaves, but instead is wearing the two bars indicative of a Navy Lieutenant.
Multiple naval officers salute each other indoors while uncovered (not wearing a hat). While it is customary to remove one's cover once indoors, saluting an officer is only performed outdoors while covered. The only instance in which officers are saluted indoors is during official ceremonies, again however, indoor saluting is only performed while covered.
Admiral King (Michael Madsen) has two silver stars on his uniform to indicate his rank. However, the stars on his collar are incorrectly positioned. Admiral stars should be stacked vertically on one's collar, not horizontally.
Admiral is wearing a hat with Coast Guard officer insignia.
Sailors on board a naval vessel do not wear camouflage clothing of any description or color scheme.
Obviously filmed on a tourist attraction ship as revealed by signs above two doorways on the deck with one saying PORT and the other saying STARBOARD, sailors would obviously know this. Also a sign at the bottom of a hatchway saying WATCH YOUR STEP and lastly a sign spotted above the Captain as he gives his rousing speech near the end which says ADDITIONAL VIEWING AREA.
Around 11 minutes in when Michael Madsen's character is talking to the Captain outside the ship, they are standing between a porthole and a door. Whenever the Captain is shown, the reflection in the porthole next to him shows a building and a water tower in the background, clearly showing that the ship is still docked and not in the middle of the ocean.
when the ship blew up, there's no way the lifeboats in the near vicinity would have continued to float peacefully, and the people in them certainly could not have stood and saluted the destroyed ship.