The Tang-class submarines were the first submarines designed and built by the United States Navy after WWII. They incorporated the best features of the high-speed German Type XXI U-boat and the venerable U.S. Navy fleet submarine. The Tang-class, with the fleet submarines converted under the Greater Underwater Propulsion Power (GUPPY) program, had much higher submerged performance than their predecessors, but were quickly surpassed by the nuclear-propelled submarines that entered service beginning in 1954. Six units in total were built.

The Ship Characteristics Board was a unit of the United States Navy.