HMS Stubborn was an S-class submarine of the Royal Navy, and part of the Third Group built of that class.

Stubborn spent the war in home waters, operating off the Scandinavian coast, and in the Pacific Far East.

She was then sent to Devonport for major repairs, where Lt. Cdr Alastair Mars saw her and described her thus: "I myself, then busy with the fitting-out of Thule, met Duff after arrival and examined Stubborn in the drydock.

She gave the impression of a skeleton's chest; for her ribs protruded whilst between them, her steel plates had been pressed inwards to form concave curves, this bizarre effect providing unforgettable tribute to the workmanship of the men who built her.

The wreck is located about 3 nautical miles (5.6 km) north-east of St Paul’s Bay and sits upright at a depth of 57 metres (187 ft).