When war broke out, Dealey's practical qualifications led to assignment as commanding officer of the new-construction , which he commissioned on December 2, 1942, less than a year after the
Attack on Pearl Harbor. After a shakedown off the East Coast, Dealey survived a "
blue-on-blue" attack by a Navy patrol bomber in the
Caribbean Sea to bring
Harder to the Pacific in the spring of 1943.
First patrol Harder left
Pearl Harbor,
Hawaii on her first war patrol on June 7, 1943, bound for the coast of southern
Honshu. In Dealey's first attack on a two-ship enemy
convoy late on the night of June 21, the submarine was driven down deep by an aggressive enemy escort and crashed into the muddy bottom – an inauspicious beginning, even though it now appears that one enemy target may have been damaged. Dealey backed the submarine out of the mud, and two nights later had his first real success in
torpedoing the Japanese seaplane tender (7,000 tons) and crippling the enemy ship so badly that it was beached on the Japanese mainland and abandoned as a total loss. Over the next four days, Dealey made seven attacks on three different enemy ship convoys, but post-war analysis credits him only with possible damage to one enemy ship. Continuing his war patrol, Dealey next scored his first of four successes against the toughest target of all – an enemy Japanese destroyer. Spotted by an enemy aircraft north of the Western Carolines on April 13, 1944,
Harder became the quarry of a patrolling enemy destroyer , which closed to within before Dealey fired a spread of torpedoes. The destroyer sank within five minutes. Dealey's ensuing contact report quickly became famous: "Expended four torpedoes and one Jap destroyer". Four days later, Dealey also sank
Matsue Maru (7,000 tons) near Woleai – then surfaced again near the island on April 20 to bombard the beleaguered Japanese garrison with his submarine's deck gun.
Harder ended its fourth war patrol at
Fremantle, Australia, on May 3, 1944.
Hayanami blew up virtually overhead, and one of her sisters subjected
Harder to a two-hour depth charge attack. By 17.30, there were eight hunting him. Dealey slipped away.
Harder transited the Sibutu Passage to pick up the guerrilla force on the night of June 8/9 and headed back early the next day. Ultimately, Christie agreed Dealey could take
Harder out for one more patrol, her sixth. Dealey left Fremantle on August 5, 1944, commanding a three-sub wolfpack, joined by (
Chester Nimitz, Jr.) and (
Frank E. Haylor, who replaced
John Broach). Their objective was the destruction of Japanese shipping off the west coast of the Philippines, south of the
Luzon Strait. After being informed (thanks to a contact report from
William Kinsella's , himself guided by
Ultra) holed up in
Paluan Bay in northern
Mindoro,
Harder and
Haddo joined three other U.S. submarines (, , and Kinsella's
Ray, with only four torpedoes remaining), all under Dealey's command (as senior officer present afloat). When the enemy convoy sortied at 05.45 on August 21, It became apparent the enemy minesweeper had been successful on August 24 in ending their extraordinary run. Indeed, after the war, Japanese records showed an antisubmarine attack that morning off
Caiman Point had resulted in oil, wood chips, and cork floating in the vicinity. Dealey's death produced waves of "profound shock" and grief through the entire Submarine Force. Dealey's loss is still blamed on fatigue by some, such as Lynch. It widened the gulf between Christie and Lockwood. In addition, Christie's attempt to nominate Dealey for a Medal of Honor was thwarted by Admiral
Thomas C. Kinkaid, who argued the award of an Army
Distinguished Service Cross for the patrol precluded any Navy decoration. In the final analysis, Dealey had sunk 16 enemy ships, with total tonnage of 54,002 tons (according to the
postwar accounting) – enough to make him number five among U.S. submarine skippers in World War II. ==World War II summary==