Lieutenant Commander Thomas Dodge, currently the executive officer of the Los Angeles-class attack submarine USS Orlando under its commanding officer Commander Carl Knox, is being considered for a third time to captain a submarine. He has been previously rejected because of his unorthodox command methods that include a "brushing" incident with a Russian submarine near the port of Murmansk, Russia, and a genital tattoo reading "Welcome Aboard" that he acquired afterward while drunk on shore leave. If denied again, he will be dismissed from the Navy's submarine command program.

Rear Admiral Yancy Graham, who dislikes Dodge, opposes his promotion, but Vice Admiral Dean Winslow, Commander, Submarine Force Atlantic, who likes Dodge and his methods, selects him to participate in a war game to test the Navy's defenses against attack from diesel-powered submarines. As Russia has been selling off their diesel fleet to America's adversaries, Winslow orders him to restore the rusty World War II-era Balao-class diesel-powered submarine USS Stingray, assigned to him by Graham, and use it to "invade" Charleston Harbor undetected, and if successful, to sink a dummy warship in Norfolk Harbor with two live torpedoes. Though initially reluctant to participate, Dodge offers Winslow a wager: if he successfully completes both tasks, Winslow will give him a nuclear submarine to command. Winslow agrees to consider it, subtly instructing Dodge to "think like a pirate" instead of following the conventional war-game rules.

Graham, boasting that he has never lost a war game and motivated by his own ambition to obtain a third star, handpicks "the crew from hell" for Stingray: hot-tempered, uptight Lieutenant Martin G. Pascal as the executive officer; crusty civilian naval contractor Howard as the Chief Engineer; rebellious Engineman 1st Class Brad Stepanak; ultra-sharp-eared Sonar Technician 2nd Class E.T. "Sonar" Lovacelli; compulsive gambler Seaman Stanley "Spots" Sylvesterson; former losing college basketball player Seaman Jefferson "Stoneball" Jackson; shock-prone (and shock-addled) Electrician's Mate Michael Nitro; and not-so-Culinary Specialist Second Class Buckman as Stingray's cook. Additionally, Graham assigns Lieutenant Emily Lake as Stingray's Diving Officer to see if women can successfully serve aboard submarines.

Using a storm off the Carolina coast as a diversion, Dodge and his crew offset their technological disadvantage by disguising the Stingray as a fishing trawler to infiltrate Charleston Harbor and set off signal flares. Upset at losing the first part of the war game and desperate to defeat Dodge, Graham halves the game's containment area without Winslow's authorization. Running into trouble on their first attempt at Norfolk Harbor, Dodge leaves the containment area and heads out to sea, breaking all contact with the Navy. Irate at this lapse in protocol, Pascal openly accuses him of hijacking his own boat and attempts to usurp him. Stingray's crew, weary of Pascal's berating and harassment, turn against him, and Dodge charges him with attempted mutiny. On deck, Lake witnesses Dodge and the crew, wearing makeshift buccaneer outfits and speaking like pirates, commit a mock execution by making a blindfolded Pascal walk the plank into the raised net of a waiting fishing trawler that will take him ashore.

During the Stingray's second attempt at Norfolk, Graham, hellbent on stopping Dodge, assumes command of the Orlando from Knox. Dodge employs an incredibly dangerous maneuver: passing Stingray between the huge propellers of a commercial supertanker to avoid sonar detection by the naval ships and aircraft protecting the approach to Norfolk. By the time Orlando eventually locates, pursues, and targets the Stingray, Dodge has fired two live torpedoes at 900 yards (820 m) into a target ship anchored in Norfolk Harbor, thereby humiliating Graham and winning the war game.

After Dodge's crew returns to port, Winslow chastises Graham and denies his promotion for attempting to undermine Dodge's success. He then congratulates Dodge, informing him that he will now be given command of a new Seawolf-class submarine, along with a "proper crew" to man her. Dodge respectfully requests that his entire Stingray crew be transferred with him, to which Winslow agrees, also revealing that Stepanak is his son, despite having his mother's surname. After Dodge dismisses his crew to begin a well-earned shore leave, Lake casually asks him as both of them leave the dock, "What exactly is this tattoo I keep hearing about?".

• Kelsey Grammer as Lieutenant Commander Thomas "Tom" Dodge, Commanding Officer, USS Stingray (formerly Executive Officer, USS Orlando)
• Lauren Holly as Lieutenant Emily Lake, Diving Officer, USS Stingray
• Rob Schneider as Lieutenant Martin G. "Marty" Pascal, Executive Officer, USS Stingray
• Harry Dean Stanton as Howard, Stingray's Chief Engineer, a civilian contractor
• Rip Torn as Vice Admiral Dean Winslow, Commander, Submarine Force Atlantic (COMSUBLANT)
• Bruce Dern as Rear Admiral Yancy Graham, Blue Team leader of the war game
• William H. Macy as Commander Carl Knox, Commanding Officer, USS Orlando
• Ken Hudson Campbell as Culinary Specialist 2nd Class Buckman, Stingray's Cook
• Toby Huss as Electrician's Mate Michael "Mike" Nitro, Electrician of USS Stingray
• Duane Martin as Seaman Jefferson "Stoneball" Jackson, Planesman
• Jonathan Penner as Seaman Stanley "Spots" Sylvesterson, Helmsman
• Bradford Tatum as Engineman 1st Class Bradley "Brad" Stepanak, Stingray's leading engineman and Vice Admiral Winslow's son
• Harland Williams as Sonar Technician 2nd Class E.T. 'Sonar" Lovacelli
• Patton Oswalt as Stingray Radioman (film debut)

The name of the film is a play on the title of the 1959 World War II drama Up Periscope and spoofs several titles in the submarine film subgenre, including the Cold War drama The Hunt for Red October.^[3]

Down Periscope began shooting on May 6, 1995, and finished on July 27.^[4]

USS Pampanito, a Balao-class submarine from World War II, now a museum ship and memorial in San Francisco, played the part of USS Stingray. The nearby Suisun Bay Reserve Fleet stood in for Naval Station Norfolk.

The film makes use of both standard US Navy stock footage and scenes shot specifically for the film. The target ship that is torpedoed and sunk, ending the film's war game, is both naval stock footage of the USS Fletcher and a prop shooting miniature. Fletcher was one of the most decorated ships in US Navy history. Over the closing credits, a music video is shown of the Village People and the film's cast performing "In the Navy" aboard Stingray.

Down Periscope had its US theatrical release on March 1, 1996.^[4] The film grossed $25,785,603 domestically and $37,553,752 worldwide. The film was released on home video five months later, on August 6, 1996.^[4]

On the review aggregator website Rotten Tomatoes, the film has a score of 11% from 35 reviews, with an average rating 4.1/10. The site's consensus states: "Down Periscope takes audiences on an aimless voyage for aquatic hijinks, proving there really aren't any effective sub-stitutes for a well-written script."^[5] On Metacritic, the film receive a score of 39 based on 18 reviews, indicating "generally unfavorable reviews".^[6]

Variety wrote, "The makers of Police Academy and Major League team up to take on the submarine corps [...] and the result is a testosterone comedy that’s crude fun, with a pinch of corn-pone morality. It’s good-natured, innocuous frivolity that should raise a few smiles..." However, Stephen Holden of The New York Times felt, "The tone of the acting, which is set by Mr. Grammer's blandly laid-back performance, is all wrong for a genre that demands over-the-top hamming". Holden also wrote that the film does manage to provide "a couple of amusing bits", but "The energy level of Down Periscope is so low that moments like these, which should flare hilariously, reach a wan flicker".^[7]

• Operation Petticoat (1959)

• Down Periscope at IMDb  
• Down Periscope at AllMovie
• Down Periscope at the TCM Movie Database
• Down Periscope at Rotten Tomatoes
• Down Periscope at Box Office Mojo
• Down Periscope at Metacritic  
•   Quotations related to Down Periscope at Wikiquote