The print shown on TCM is the 1937 re-release, with some bits of 1933 dialogue obviously eliminated in order to meet the stricter standards of the now enforced 1934 production code.
The destroyer shown sinking in the movie is an actual decommissioned WWI destroyer, USS Moody. Additions were made to the superstructure to replace missing sections, and scuttling charges simulated the torpedo hit.
LCDR Toler (Walter Huston) upon taking command says "Let's go below and look at your ship." Submariners refer to their vessel as a "boat," not a ship. In similar fashion, submariners while politely disdainful of their surface counterparts, joke that there are two types of naval vessels: submarines and targets.
The photographic crew devised a scheme to photograph targets through a periscope, with a series of lenses and prisms.
Considerable variations in running times were reported in reviews from press previews. Daily Variety reported a time of 155 minutes on 17 March 1933 while the Motion Picture Herald reported 78 minutes on 15 April 1933. In its review, Variety listed 105 minutes on 2 May 1933, but the TCM print was 101 minutes long.