The young men dread having to dance with the wives of admirals, but Knowlton and his close friend and shipmate, Lieutenant Ed "Brick" Walters (Robert Young), are pleasantly surprised to discover the beautiful Joan Standish (Madge Evans) among the attendees.

After the Austrians abandon ship, Toler sends Brick and three sailors to search the sinking vessel for code books.

When enemy biplane fighters attack, Toler fights them off, but the arrival of a bomber forces him to order the AL-14 to submerge and leave his boarding party behind.

There he encounters patient Flight Commander Herbert Standish (Edwin Styles), who turns out to be Joan's paraplegic husband.

Two enemy ships are sunk, but one destroyer evades the torpedoes and forces the AL-14 to dive to the sea bottom, 65 feet (20 m) below its maximum safe depth.

When Knowlton goes to the hospital to inform Joan's husband, he learns that a successful operation makes it likely that the man will recover fully.

On January 5, 1933, just after production on the film began, the entertainment trade paper The Hollywood Reporter announced that Madge Evans had "started work on it yesterday" and that MGM had changed the picture's intended release name, Pigboats, to the more sensational title Hell Below.

MGM purchased the USS Moody (DD-277), a World War I-era destroyer destined for scrapping due to the London Naval Treaty limits on navy strength, for US$35,000.

[1] Mordaunt Hall in his review of Hell Below for The New York Times, said: "... the way in which it slips from farcical doings ashore to grim sights aboard a damaged United States submersible are decidedly jarring.

Yet, in spite of its obvious shortcomings, there are scenes in the undersea craft that are extremely well pictured and so are others depicting what happens on the surface of the water.