[5] At the time it was felt that mass production of large fleet submarines would be impractical.

[7] For the Mackerels, two somewhat different designs were produced by the Electric Boat Company and Portsmouth Navy Yard.

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.

Marlin appeared as the fictional Corsair in the 1943 movie Crash Dive, filmed at Submarine Base New London.