The Oberon class was a direct follow on of the Porpoise-class, with the same dimensions and external design, but updates to equipment and internal fittings, and a higher grade of steel used for fabrication of the pressure hull.

[2] Propulsion machinery consisted of 2 Admiralty Standard Range 16 VMS diesel generators, and two 3,000 shaft horsepower (2,200 kW) electric motors, each driving a 7-foot diameter (2.1 m) 3-bladed propeller at up to 400 rpm.

[2] Otter was laid down by Scotts Shipbuilding and Engineering Company on 14 January 1960, and launched on 15 May 1961.

[2] The only Oberon class submarine fitted with a mild steel casing needed when deployed as target for practice torpedo attacks.

This article about a specific naval ship or boat of the United Kingdom is a stub.