Chief Petty Officer "Windy" Riker (Beery)is a veteran aerial gunner of a Navy Helldiver dive bomber and the leading chief of Fighting Squadron One, about to go to Panama aboard the USS Saratoga aircraft carrier. He loses his five-year title of "champion machine gunner" after young C.P.O. Steve Nelson (Gable) joins the squadron. Windy, notorious for using his fists to enforce discipline, is charged by local police with wrecking a Turkish bath. Windy is saved from arrest, however, when Lieutenant Commander Jack Griffin ( Miljan), skipper of the squadron, intervenes on his behalf. Griffin and his second-in-command, Lieutenant "Duke" Johnson (Nagle), agree that Nelson is the best candidate to replace Windy as he ponders retirement.
Pendant la Seconde Guerre mondiale, un navire de la Marine américaine est coulé par un sous-marin japonais, laissant 900 membres d'équipage échoués dans les eaux infestées de requins.
Major Cleve "Iceman" Saville (Robert Mitchum), a veteran World War II fighter ace, returns to combat, eager to fly an F-86 Sabre fighter. His commanding officer, Colonel "Dutch" Imil (Richard Egan), assigns him command of a flight.
In April 1953, during the Korean War, a company of American infantry, led by Lieutenant Joe Clemons (Gregory Peck) are to recapture Pork Chop Hill from a larger Communist Chinese army force; they recapture the hill, but are depleted, only 25 of a 135-man unit are left. They prepare for a large-scale Chinese counter-attack which they know will overwhelm and kill them in vicious fire fights and hand-to-hand fighting while the Panmunjeom cease-fire negotiations continue.
During World War II, Navy Lt. Cmdr. John Lawrence (Richard Widmark), a strict disciplinarian, is put in charge of Underwater Demolition Team 4 after its former leader, Lt. Cmdr. Jack Cassidy, is killed in action. The unit's men are distrustful of the professionally aloof Lawrence, and the relationship immediately takes a turn for the worse when they brawl with sailors aboard their transport ship. The ship's captain, Lt. Cmdr. Pete Vincent (Gary Merrill), understands the natural resentment the elite UDT men feel over the death of Cassidy, which they have transferred to Lawrence, and offers to go easy on the team at captain's mast. The "by-the-book" Lawrence, however, elects to hold his own mast and disciplines the entire team just before a dangerous reconnaissance mission to ascertain the safest landing beach during an upcoming invasion of a Japanese-held island. Lawrence is scornfully perceived as afraid when he splits up the platoon and puts team executive officer Lt. Klinger in charge of a diversion to the more dangerous beach, where the main landing is scheduled.
Flagg and Quirt are veteran United States Marines sergeants whose rivalry dates back a number of years. Flagg is commissioned a Captain, he is in command of a company on the front lines of France during World War I. Sergeant Quirt is assigned to Flagg's unit as the senior non-commissioned officer. Flagg and Quirt quickly resume their rivalry, which this time takes its form over the affections of Charmaine, the daughter of the local innkeeper. However, Charmaine's desire for a husband and the reality of war give the two men a common cause.
In 1941, Mamie Stover (Jane Russell), a San Francisco prostitute, is chased away from the city by several policemen. On a freighter to Honolulu, she meets Jim Blair (Richard Egan), a successful writer who thinks of Mamie as a Cinderella-like beauty. Flattered, Mamie enjoys not being associated with her former occupation and falls in love. A shipboard romance is cut short when Mamie notices Jim being welcomed ashore by his sweetheart Annalee (Joan Leslie).
Popular crooner Russ Raymond (Dick Powell) abandons his career at its peak and joins the Navy using his real name, Tommy Halstead. However, Dorothy Roberts (Claire Dodd), a reporter, discovers his identity and follows him in the hopes of photographing him and revealing his identity to the world.
Gus Brubaker (Dick Shawn) is a self-described schnook. His wife talks him into applying for G.I. insurance for which he is eligible from his World War II service with the Air Force. Gus is reluctant because he was shot down and became a prisoner of war, but the military had listed him as killed. A red-tape foulup results in Gus being back in uniform, assigned to a ramshackle radar station on a backwater island near Japan. The airmen assigned there are apathetic, slovenly, and unmotivated. Its equipment and supplies are a collection of junk, abandoned or surplus.
Upon the United States entry into World War I, the first American units to arrive at the front in France are veteran Marine companies, one of which is commanded by captain Flagg, along with his Lieutenants, Moore and Aldrich. Flagg has developed a romantic relationship with the daughter of the local innkeeper, Charmaine, and resumes their relationship after returning from the front. However, he lies to her and tells her he is married when she wants to come with him on his leave to Paris. Replacements arrive and their lack of discipline and knowledge infuriate the Captain. But he is expecting the arrival of a new top sergeant, who he hopes will be able to train them properly. However, when the sergeant arrives, it is Quirt, Captain Flagg's long time rival, a rivalry which quickly re-ignites.
Three decorated Navy pilots finagle a four-day leave in San Francisco. They land a posh suite at a hotel where Commander Andy Crewson (Cary Grant), a master of procurement, arranges to populate it with wine, women and song.
At Norfolk Naval Base in the opening months of World War II, Lieutenant John W. Harkness (Cooper), a newly commissioned officer, bids goodbye to wife Ellie (Jane Greer) and reports aboard the PC-1168 unaware that his civilian background in engineering and his Rutgers education has elected him, by means of a hole punched in an IBM card, to head a secret project and command the ship. The Navy has installed a steam engine and an experimental evaporator-condenser in the ship to test its feasibility in patrol craft and has assigned Harkness to conduct the sea trials.
Eddie Devane (William McNamara) is a young Seaman Apprentice who has carried out a number of inventory-related scams along with his partner-in-crime Howard (Crispin Glover) and made a lot of money during his service. A day before his discharge, Eddie is assigned to escort a prisoner from the marine base at Camp Lejeune along with the authoritarian, no-nonsense Chief Petty Officer Rock Reilly (Tom Berenger). Eddie is of course not pleased with this development. When Howard sees a grumpy-looking Eddie being escorted from his superior's office by a couple of other seaman, he thinks Eddie has been found out and arrested for his scams. In order to destroy evidence, he goes to Eddie's desk and finds the money, the existence of which Eddie had concealed from him.
Lt. Kenneth Braden, a newly trained Navy Frogman, is unexpectedly ordered to report for duty without being able to notify his new girlfriend, Sally Johnson, in whom he has taken a serious interest. He is informed that she is an officer of Naval Intelligence and was responsible for a recent confirmation of his character and fitness for a special mission.