USS Shark, a 1526-ton Balao class submarine built at Groton, Connecticut, was commissioned in mid-February 1944. She arrived at Pearl Harbor, Hawaii, in April and began her first combat operation in May. Operating west of the Marianas as part of a three-submarine attack group, she sank one Japanese freighter on 2 June, another on the 4th and two more on the 5th. This very productive patrol, which ended in mid-June, prevented the enemy from landing additional army units and thus greatly facilitated the capture of Saipan and Guam.

Shark's second war patrol, off the Volcano and Bonin Islands in July and August, produced no sinkings but did result in the rescue of two Navy airmen from a downed torpedo plane. Her third patrol, to the waters south of Formosa, was another three-submarine "wolf pack" operation. Shark left Pearl Harbor in September and, on 24 October 1944, is believed to have sunk a Japanese ship carrying American prisoners of war from the Philipines to Japan. She was not heard from again and may been lost to enemy antisubmarine attack on the same day, possibly while attempting to rescue some of the POWs. Shark's entire complement, nearly ninety officers and men, perished with her.