HMS NARWHAL (Lt Cdr R J Burch) was operating off the coast of Norway in July 1940. At 1455 on 23 July, a Dornier 17Z piloted by Leutnant zur See Muller sighted a fully surfaced submarine in approximate position 56’52’N, 01’40’E.

The aircraft attacked with machine-gun fire and released three 50 kg bombs from a height of 80 metres. One of the bombs scored a direct hit three metres abaft the conning tower. The other two were near misses. The submarine immediately began to settle by the stern until she had assumed a vertical position, her bows protruding three to four metres above the surface of the sea.

She remained thus for two to three minutes before finally disappearing beneath the surface. The aircraft returned to the position of the attack and saw wooden wreckage, traces of oil and what looked like half a lifebelt floating on the surface. There were no survivors.

The submarine was officially declared lost on 1 August 1940.