The Porpoise-class was the first class of operational submarines built for the Royal Navy after the end of the Second World War, and were designed to take advantage of experience gained by studying German Type XXI U-boats and British wartime experiments with the submarine Seraph, which was modified by streamlining and fitting a bigger battery.

[1] Propulsion machinery consisted of two Admiralty Standard Range diesel generators rated at a total of 3,680 brake horsepower (2,740 kW), which could charge the submarine's batteries or directly drive the electric motors.

In February 1960, Rorqual visited the Mediterranean, calling at La Spezia in Italy and Nice in southern France before returning home to Faslane at the end of the month.

An explosion in 1966 killed one junior rate and injured the chief of the watch, who died ashore at Inhambane, Rorqual was off the coast of Mozambique en route to Singapore.

In 1969, Rorqual rammed a moored minesweeper, USS Endurance (MSO-435) while docking at River Point pier in Subic Bay, Philippines.