Mackerel - class submarine The " Mackerel " - class submarines were a pair of experimental prototype submarines built just prior to World War II and launched in 1940 and 1941 . The two submarines were similar in size and capability to the S - class submarines built at the end of World War I , and had been ordered to test the feasibility of using mass production techniques to build small submarines . Until at least 1940 it was thought that mass production of fleet submarine s would be impractical , and in any case small submarines could provide area defense for submarine bases . Once it became apparent that there would be sufficient production of the more capable Gato - class submarine s , interest in the design waned and no additional small submarines were ordered . Submarine production standardized during the war on the Gato class and its successors , the Balao and Tench class submarines . In some references , the " Mackerel " s are called the " M - class " . Design . The " Mackerel " s stemmed from design studies ordered by the Navy ' s General Board beginning in 1936 , when Admiral Thomas C . Hart joined the Board and spearheaded the small submarine effort . At the time it was felt that mass production of large fleet submarine s would be impractical . It was also felt necessary to replace the aging S - boats , R - boats , and O - boats , to provide area defense for submarine bases and operate in restricted waters . For the " Mackerel " s , two somewhat different designs were produced by the Electric Boat Company and Portsmouth Navy Yard . As prototypes , " Mackerel " and " Marlin " were near - sisters rather than sisters . References agree that " Mackerel " used a direct drive propulsion arrangement , but differ as to whether " Marlin " had direct drive or diesel - electric drive . Both had engine designs not used in other US Navy submarines ; " Mackerel " an in - house Electric Boat design , " Marlin " an ALCO locomotive design . By late 1941 it became apparent that fleet submarines could be mass - produced , and interest in small submarines began to wane . Interest in them was revived with the examination of the German " U - 570 " , a Type VII U - boat captured by the British and loaned to the US . Also , Admiral Hart returned to the General Board in late 1942 , following a courageous part in the ultimately futile defense of the Philippines and Indonesia in 1941 - 42 . He pointed out that no other navy had abandoned small submarines . However , Admiral Frederick J . Horne , Vice Chief of Naval Operations , felt that small submarines should only be built if there was no interference with fleet submarine production . With all submarine yards capable of building fleet submarines , there was no easy way to avoid impacting their production , so the small submarine was abandoned as a concept . Service . Both submarines spend their entire careers operating from Submarine Base New London , Connecticut and Portsmouth Navy Yard in training and research roles , contributing to the development of both submarine and antisubmarine warfare in World War II . On 12 April 1942 " Mackerel " was attacked by a German U - boat while transiting to Norfolk , Virginia , but the torpedoes missed and " Mackerel " ' s counter - attack was unsuccessful . Unsubstantiated reports claim that in February 1942 , both vessels of the class engaged and sank the giant Free French Navy submarine , " Surcouf " , after discovering her in Long Island Sound refueling a German U - boat , which was also sunk . " Marlin " appeared as the fictional " Corsair " in the 1943 movie " Crash Dive " , filmed at Submarine Base New London . After the war , both boats were decommissioned in November 1945 and scrapped in 1946 - 47 .