This film inspired many comparisons to Destination Tokyo (1943) and, in fact, uses some underwater footage from the earlier film despite being in black and white. This production did not bother to tint the black and white footage blue, but since the underwater shots were already quite dark, it helped to slip them by 1950s audiences.
The film casually uses terms and references particular to the military of the time. When briefing Lieutenant Braden on his mission, Commander Stevenson reminds him that he is "not to be captured". This is not stating the obvious but is code for suicide-if-captured. He then refers to Braden as a "90-day wonder". This was military slang for lieutenants, who were often college-educated men who entered the military at the very lowest grade of officer in times of war, after having had only the most basic training possible. Malone refers to another submarine as a "sewer pipe". Braden quietly refers to Commander Stevenson as "Captain Bligh" to Malone, which is code for a tyrant, based on the legendary British naval captain of the HMS Bounty. A radar crewman uses the term "bogey", which is military slang for an unidentified presence which could be hostile. When Braden pops in on radio crewmen Shelton, he asks him what he's got there "the Milkman's Matinee?" This was a radio program famous for its long, all-night broadcasts designed to entertain Americans who worked graveyard shifts, like police, firefighters, cabbies, and milkmen.
When this film was bring made, James Garner was being positioned as a Rock Hudson type, with the intention of establishing him as a leading man on the big screen. He did not have as strong an appeal as hoped. so he then focused on TV.