, a Gato-class submarine, was the first submarine and second vessel of the United States Navy to be named for the shad, a fish of the herring family, common along coasts of the United States. The second Shad was laid down by the Portsmouth Navy Yard (in Kittery, Maine) on 24 October 1941. She was launched on 15 April 1942 (sponsored by Miss Priscilla Alden Dudley), and commissioned on 12 June 1942, with Lieutenant Commander Edgar J. MacGregor III (United States Naval Academy class of 1930) in command. Atlantic war patrols Following shakedown off the New England coast, Shad departed on a special patrol as a unit of Submarine Squadron (SubRon) 50 to a point off the coast of Mehdiya, French Morocco, to conduct reconnaissance in preparation for Operation Torch, the Allied occupation of North Africa. Upon completion, she sailed to Roseneath, Scotland, for repairs and further training. Shad'''s second war patrol was conducted in the Bay of Biscay and Spanish coastal waters with other units of SubRon 50 under British command. Although the most of the vessels she sighted were neutral Spanish ships, the submarine sank an enemy trawler, a barge, and severely damaged a destroyer escort before she returned to Roseneath for refit on 12 February 1943. With refitting completed, Shad departed Scotland for her third war patrol on 7 March, again heading for the Bay of Biscay. During this mission, the submarine damaged the blockade runner Pietro Orseolo, before returning to Scotland on 12 April.Shad's fourth patrol, conducted in Norwegian waters, and fifth war patrol, conducted en route back to the United States, were uneventful. Sixth war patrol Following repairs in New London, the submarine was transferred to the Pacific front. Arriving at Pearl Harbor on 7 September, Shad underwent two weeks of voyage repairs and then departed on 28 September, for her sixth war patrol, and her first against the Japanese. This patrol was also the first American wolfpack, comprising Shad, , and , commanded from Cero by Captain Charles Momsen. Just before dawn on 22 October, Shad attacked a convoy of two cruisers and three escorts. After firing 10 torpedoes, she was forced to head for deeper water to evade the depth charging that followed. Although no positive evidence of any sinkings was found, a two-square mile oil slick confirmed the damage done by the submarine. Shortly after midnight on 27 October, Shad sighted another