During the hostilities of WWII no American submarines ever entered Tokyo Bay. They did operate in the outer bay (Sagami Bay) but Tokyo Bay was too shallow and narrow to operate in. The average depth of Tokyo Bay is 130 feet which is insufficient for a submarine to safely operate in combat conditions. Periscope depth was approximately 60 feet. In the right conditions a submarine could be seen by aircraft even at that depth.
At various points in the movie characters make comments as to how fast they surfaced or dived the submarine. During the war crews practiced the dive process so that from the order to dive they could arrive at periscope depth (60 feet) in about 45 or 50 seconds. In actual practice there was no "crash dive" as is often seen in movies. Every dive was carried out as quickly as possible to insure readiness in actual combat conditions.
Archer 'Archie' Sloan's name may be a reference to the U.S.S. Archerfish, which in 1944 sank the Japanese super-carrier Shinano, the largest warship ever sunk by a submarine.
This film failed at the box office, resulting in a loss to MGM of $195,000 according to studio records.
Like some well known actresses who favored being photographed from the left side, Glenn Ford likewise adheres to this regimen, filmed from the left, but lit from the right, throughout the film, from beginning to end.