Down Periscope - Plot

Plot

Lieutenant Commander Thomas Dodge (Kelsey Grammer), a capable yet unorthodox US Navy officer, is about to be denied command of his own submarine for a third time because of his unconventional ways. Failure to secure a command will result in him being dropped from the command program and an assignment to a desk job, and he is particularly opposed by Rear Admiral Yancy Graham (Bruce Dern).

Vice Admiral Dean Winslow (Rip Torn) finds the perfect use for Dodge, however, when Winslow launches a war-game to test the Navy's defenses against possible attack by old diesel submarines in the hands of terrorists or other enemies of the US. Among those defenses being tested is the Navy's newest sub, the Los Angeles-class USS Orlando, which will be commanded by Commander Carl Knox, Dodge's former CO (William H. Macy). For this purpose, Dodge gains command of the rusty World War II era Balao-class diesel sub, the USS Stingray, SS-161.

Adm. Winslow gives Dodge the order to "don't go by the book" and to "think like a pirate" and advises that if he can win the war-game, including sinking a mock target in Norfolk harbor, Winslow will consider Dodge for command of a nuclear submarine.

Adm. Graham, motivated by his dislike for Dodge and his own ambition, arranges circumstances to make Dodge's mission even more difficult. Graham handpicks a motley crew for the Stingray consisting of rejects and misfits: hot-tempered and uptight Lieutenant Martin Pascal (Rob Schneider) as Executive Officer, crusty Chief Engineer Howard (Stanton)(Civilian contractor, no active Naval personnel familiar with a Balao-class engine system), rebellious Engineman 1st Class Brad Stapanek, sharp-eared Sonar Technician 2nd Class E.T. "Sonar" Lovacelli, compulsive gambler Seaman Stanley "Spots" Sylvesterson (Jonathan Penner), former U.S. Naval Academy basketball player Jefferson "R.J." Jackson (Duane Martin), who has dreams of playing in the NBA, shock-prone (and shock-addled) electrician Seaman Nitro, and the not-so-culinary cook Seaman Buckman (Ken Hudson Campbell).

To further frustrate Dodge, Graham also uses the Stingray to institute a pilot program by the Navy for evaluating the feasibility of women serving on submarines, knowing that the diesel boat is unsuitable for mixed-gender living; Lieutenant Emily Lake (Lauren Holly) joins the crew as Diving Officer.

Using unorthodox tactics to offset their technological disadvantage, Dodge and the Stingray crew win their first objective by getting into and setting off flares in Charleston Harbor. Desperate to defeat Dodge, Graham cuts the containment area for the war-game in half without authorization. Running into trouble on their first attempt at Norfolk harbor, Dodge leaves the exercise area. Irate at this lapse in protocol, the zealous by-the-book Pascal attempts to gain command of the Stingray, but no one supports him. Without support, his attempt is considered mutiny and, thinking like a pirate, Dodge makes him walk the plank into a fishing trawler.

During the Stingray's second attempt at Norfolk, Graham assumes personal command of the Orlando. After some risky maneuvers by the Stingray, the Orlando is able to chase her down and obtain a shooting solution, but not before Dodge launches two torpedoes into a target hulk, which gains him the victory.

Upon the Stingray's return to port, Adm. Winslow congratulates Dodge on a job well done and confides that crewman Stapanek is his own son. The admiral informs Dodge that he will not get a Los Angeles-class submarine as the two had previously discussed, but instead a Seawolf-class submarine, which is a newer and much larger craft, plus a "proper crew" along with it. Dodge turns down the latter notion, requesting to transfer the entire crew of the Stingray. He then launches a romantic mission with Lt. Lake.

Closing credits include a music video of the Village People and the film's cast performing "In the Navy".