John Blackburn was born in 1923, the son of Lieutenant Commander James Alexander Pollard Blackburn (a submariner) and Hilda Kate Blackburn (née Stanford).  He joined the Royal Navy as a Cadet in May 1936.  Promoted to Midshipman on 1 May 1939, on 1 May 1940 he was appointed to the battleship HMS RODNEY.  He was promoted to Sub Lieutenant on 15 February 1942.

He joined submarines and was appointed to the submarine base HMS TALBOT ‘for Submarines’ on 21 August 1942 and for ‘Submarine HMS SAFARI as 3rd Hand’ on 25 November 1942.  He was promoted to Lieutenant on 1 July 1943 and he returned to HMS TALBOT on 21 August 1943.  John Blackburn was awarded the Distinguished Service Cross – see London Gazette dated 6 July 1943.

John Blackburn was appointed to the Submarine Depot Ship HMS CYCLOPS at the Holy Loch ‘for Submarine HMS SEALION as First Lieutenant’ on 11 November 1943 and then returned to HMS SAFARI as First Lieutenant on 4 March 1944.  An appointment to HMS TIPTOE as First Lieutenant followed on 15 April 1944.

He successfully completed his ‘Commanding Officers Qualifying Course’ from February 1948 and was then appointed in command of HMS TOKEN on 11 May 1948.  John Blackburn returned to General Service on 25 April 1949 joining the Cruiser HMS DEVONSHIRE.  The April 1951 Navy List shows that John Blackburn was appointed in command of HMS AFFRAY.

On 16 April 1951, HMS AFFRAY sailed from HMS DOLPHIN to take part in training exercises and was carrying a class of trainee submarine officers and a team of Royal Marine Special Forces.

On the morning of the 17 April the submarine failed to report her position as instructed.  SUBMISS and SUBSUNK procedures were initiated and, after extensive searches, AFFRAY was eventually located in the Hurd Deep, in the Channel, in June 1951.  AFFRAY was lost with all hands in unknown circumstances although after the wreck was found photographs showed that the snort mast had been broken off.

John Blackburn of The Cottage, Foster Road, Alverstoke, Hampshire was married to Margaret Jean Gertrude Blackburn (née Cowan), a former WREN.  There were two children – a son aged six and a daughter aged four.