Editing Balao-class submarine (section)

===Transport submarine===
[[File:USS Sealion;0831502.jpg|thumb|A [[Sikorsky H-19 Chickasaw|Sikorsky HRS]] helicopter touches down on ''Sealion'' as a transport submarine]]
{{USS|Sealion|SS-315|2}} and {{USS|Perch|SS-313|2}} were converted to amphibious transport submarines in 1948 and redesignated as SSPs. Initially, they were equipped with a watertight hangar capable of housing a [[Landing Vehicle Tracked]] (LVT), and retained one {{convert|5|in|adj=on}}/25 caliber deck gun for shore bombardment. Both torpedo rooms and one engine room were gutted to provide space for embarked [[United States special operations forces|Special Operations Forces]] (SOF) and their equipment. Snorkels were fitted. Due to the extra personnel, to avoid excessive snorkeling they were equipped with a [[Carbon dioxide scrubber|{{CO2}} scrubber]] and extra oxygen storage. Initially, a squadron of 12 SSPs was considered, capable of landing a reinforced Marine battalion, but only two ''Balao''-class SSPs (out of four overall) were actually converted. ''Perch'' landed [[British commandos]] on one raid in the [[Korean War]], and operated in the [[Vietnam War]] from 1965 until assignment to [[United States Navy Reserve|Naval Reserve]] training in 1967 and decommissioning in 1971, followed by scrapping in 1973. ''Perch'' was replaced in the Pacific Fleet transport submarine role by {{USS|Tunny|SS-282|2}} in 1967 and {{USS|Grayback|LPSS-574|2}} in 1968. ''Sealion'' operated in the Atlantic, deploying for the [[Cuban Missile Crisis]] and numerous SOF-related exercises. She was decommissioned in 1970 and expended as a target in 1978. The LVT hangar and {{convert|5|in|adj=on}} gun were removed from both boats by the late 1950s. They went through several changes of designation in their careers: ASSP in 1950, APSS in 1956, and LPSS in 1968.<ref>Friedman since 1945, pp. 86-88</ref><ref name="Register"/>