The exterior shots of the subs and torpedoes do not match the surrounding topography during the battle in the canyon.
During the end, the submarine is in a step dive according to the exterior shots, but the sub is level in interior shots.
At the beginning of the movie the words, "Oceana N.A.S., Norfolk, VA", appeared in the screen. The Navy does not keep their submarines at air stations. N.A.S. = Naval Air Station
The officer white uniforms are shown with collar devices and shoulder boards to display rank, collar devices are used on the khaki uniform not the white. The white uniform should have rank on the shoulder boards only.
A warning message appears on the submarine's control panel in which the word 'bouyancy' is mis-spelled as 'bouyency'.
At the beginning of the movie the words, "Oceana NAS, Norfolk, VA", appear in the screen. NAS stands for Naval Air Station. The US Navy does not use Naval Air Stations for ships.
When Carter and a man jumps from the helicopter into the sea, they are not wearing oxygen cylinders or diving fins and other equipment. One minute later the camera is showing them diving underwater in full diving gear, with O2 tanks and in diving fins.
The positions are given in latitude and longitudes, but without any geographical markings (North, South, East, West), although it could be taken for granted that their positions would be North and East due to their location.
Opening scene is actually the Long Beach Naval Shipyard, not Norfolk. The Queen Mary and the old Spruce Goose dome are both visible in the background at 0:28.
Gunther Newton's green-card is expired -1990. Trusting an expired card. The release of this movie is 1996. Also, the photo is covering the SSI number -- also, trusting
this piece of intel.
1:26:49 Lt. Cmdr. Lisa Stark has a conversation with Richter that reveals he knows she has "a man on board." She has no idea whether or not he is alive, yet immediately gives command to "better send a message to Carter" without confirming he is not compromised.