On 5 January 1940 HMS Starfish (Lt. Thomas Anthony Turner, RN) sailed from Blyth. On 9 January 1940 she attacked a German minesweeper off the German North Sea coast in the Heligoland Bight in position 55.00N, 07.10E. However this attack failed because, due to drill error, the torpedoes remained stuck in the tubes(!).
She returned for second attack but the hydroplanes jammed and the CO decided to bottom for the remainder of day to carry out repairs in about 27 metres of water. The German minesweeper M-7 located her & dropped 2 DCs which did no damage, but @ 1050 hrs one of the electricians asked for permission to restart one of the Sperry motors to prevent the gyro from wandering, it was granted and, no sooner the motor started, 4 DCs rained on top of the boat, fairly close aboard, causing widespread damage.
At 1440 another DC attack was carried out, 20 of these falling fairly close to the hull, shearing rivets & starting plates which began leaking. by 1800 hrs the situation inside was serious, the engine room crankcases and starboard main motor bearings were flooded, the torpedo trenches & bilges were full, water was pouring through the starboard engine clutch and lapping the starboard main motor casing.
Starfish laid on the bottom until the CO, having formed the opinion the enemy was not likely to leave the vicinity in the near future, at 1820 hrs gave the order to surface. In order to accomplish this, the sub was forced to drop the ballast keel, barely making it due to loss of HP air and water in the hull, coming up at a 45° angle. She sank very shortly with no loss among the crew, which was picked up by the waiting ships and taken as POWs.

Commanding Officer:
Lt. Thomas Anthony Turner, RN
15 April 1939 - 9 January 1940