Correct me if I'm wrong but the submarine in the movie has gotta be the same or at least the same class as the boat used in "CRASH DIVE" from 1943, rite? I know it was probably imposable to get a real Japanese I-Boat. Just wondering that's all!
Well, the sub in the film was a model, not a real one. What real type of submarine the model was modeled after I do not know. But it wouldn't be surprising if they re-used the model sub from Crash Dive, or at least from some other 20th Century Fox film. I doubt many viewers could tell what kind of sub was being depicted.
All such water scenes in films made at Fox in that era were shot in the so-called "Sersen Tank", a large outdoor water tank used for filming special effects sequences for films set on or under the water, where it was impossible or too expensive to build real ships and film on the ocean. It was named after Fox's longtime special effects director, Fred Sersen, whose name you can see in most Fox credits through the early 50s. Crash Dive, The Black Swan, Down to the Sea in Ships, Hell and High Water, The Enemy Below and many other Fox films utilized the tank. The last Fox movie filmed using the Sersen Tank was 1961's Voyage to the Bottom of the Sea, after which the land on which the tank stood -- which also included the classic Fox "western town" set, along with many other long-standing sets -- was sold to developers to generate income for the cash-strapped studio. A load of irreplaceable Hollywood history was lost due to that sale. This land is the site of the present-day Century City complex.