| Director | Robert Wise |
|---|---|
| Box office | $2.5 million |
A World War II US Navy submarine officer, Commander P.J. Richardson, is determined to get revenge on the Japanese destroyer Akikaze and its captain, nicknamed "Bungo Pete," who has sunk four U.S. submarines in the Bungo Straits, including his previous command. He persuades the Navy Board to give him a new submarine command with the provision that his executive officer be someone who has just returned from active sea patrol.
He single-mindedly trains the crew of his new boat, the USS Nerka, to return to the Bungo Straits and sink Bungo Pete, in spite of the Navy having expressly forbidden him from entering the Bungo Straits on this mission. Richardson's executive officer, Lieutenant Jim Bledsoe, resents Richardson and the Navy leadership for denying him command of the Nerka, and worries about the safety of his boat and his crew.
Richardson rigorously drills the crew on a rapid bow shot. Firing at the bow of an approaching ship is considered an act of desperation due to a vessel's extremely narrow profile. He bypasses one target, then takes on a Japanese destroyer with a bow shot. The crew figures out that Richardson is avoiding legitimate targets to enter the Bungo Straits undetected in direct violation of his mission orders.
They encounter a large Japanese convoy. After blowing up a cargo ship and engaging Bungo Pete, they are attacked by aircraft that had clearly been alerted to their presence and were waiting in ambush. They rapidly dive and barely survive depth charges. Three of the crew are killed, and Richardson suffers an incapacitating concussion. The submarine narrowly dodges what the crew mistakenly believes is one of their own torpedoes doubling back on them. By sending up blankets, equipment and the bodies of the dead, they convince the Japanese that the submarine has been sunk. Bledsoe uses Richardson's injury to assume command and set course for Pearl Harbor.
While listening to Tokyo Rose proclaiming the sinking of their boat, several crewmen are mystified about how the Japanese are able to identify several of them by name. Bledsoe realizes that the Japanese have analyzed their floating trash. Since the Japanese believe the Nerka has been sunk, he returns to the Bungo Straits to fight the Akikaze, which the submarine sinks with a bow shot, only to be attacked again by a mystery torpedo. Richardson deduces that the Akikaze was not working alone to sink US submarines but was in concert with a Japanese submarine. He orders the boat into a dive just seconds before a Japanese torpedo races by.
After a brief underwater standoff, Bledsoe realizes that with the Akikaze gone, the Japanese sub must defend its convoy. By attacking the convoy, the Nerka forces its adversary to surface, where it uses the shallow-draft decoy ship as a screen. The Nerka fires torpedoes under the shallow-draft ship, destroying the Japanese sub hiding behind it.
Richardson collapses on the bridge, dies, and is buried at sea.