Sea Leopard, along with other units of SubRon 6, set sail for the Caribbean and operation "Springboard." She then returned to Norfolk for local operations until March 1957, when she again joined the Sixth Fleet in the Mediterranean. In June, she participated in festivities celebrating the 50th anniversary of the Netherlands Submarine Force at Rotterdam, before sailing to Charleston, South Carolina, for an overhaul. Upon its completion in January 1958, Sea Leopard joined operation "Springboard" in the Caribbean and then returned to Norfolk for local operations. Joining Task Group Alfa, she participated in operations to develop antisubmarine warfare tactics and readiness, until undergoing restricted availability at Charleston Naval Shipyard (August to October 1959) to install a new high capacity battery. 1960s During 1960, Sea Leopard operated in the Atlantic in training exercises and fleet operations until 23 October, when she entered Philadelphia Naval Shipyard for overhaul. Following completion in April 1961, she returned to Norfolk and operated locally until 19 August when she joined Task Force 69 in the Mediterranean to participate in NATO operation "Checkmate" and visit Rota, Spain; Malta and Naples, Italy. On 3 October, Sea Leopard sailed from the Mediterranean for northern Europe and NATO operation "Devil Spread." Arriving back at Norfolk on 10 November, she again joined Task Group Alfa for antisubmarine warfare (ASW) training until February 1963. She then participated in operation "Springboard" in the Caribbean. Immediately following the loss of Thresher on April 10, 1963, she conducted an at-sea helicopter transfer of a crew member who had left the Thresher just three weeks earlier. In July, Sea Leopard rejoined Task Group Alfa, until entering Norfolk Naval Shipyard on 16 December for an overhaul. In October 1964, after refresher training out of New London, Connecticut, the submarine returned to Norfolk to resume normal duties as a unit of SubRon 6, providing ASW services to units of the Second Fleet. In March 1965, she joined Task Group Alfa, deploying to the Mediterranean and then returning to the Atlantic to participate in ASW exercises with that group until 24 November 1966. On 27 December, Sea Leopard entered Norfolk Naval Shipyard for overhaul. In July 1967, she conducted type training with submarines and . The remainder of 1967 was spent in the Norfolk area. In 1968, Sea Leopard participated in exercises "Aged Daddy V" and "Rugby Match," and joined the search for the ill-fated submarine . From July