Edwin Pratt was born in Devonport, Devon on 4 May 1905, the son of Edwin Pratt (Chief Petty Officer, Royal Navy) and Edith Ellen Pratt. Edwin Pratt (Junior) joined the Royal Navy as an Engine Room Artificer Apprentice on 6 August 1921. After completing his five-year Apprenticeship, he served in the battleship HMS REVENGE, the destroyers HMS WESTMINSTER, HMS WAKEFUL and HMS WESTMINSTER again, before serving in the battleship HMS ROYAL SOVEREIGN.

Edwin Pratt was next sent to the Mediterranean to join the destroyer HMS WOLSEY. After returning home, he was advanced to Chief Engine Room Artificer Second Class and then served in the destroyer HMS SANDWICH before being promoted to Warrant Engineer on 1 July 1939. In April 1940 Edwin Pratt was serving in the battleship HMS REPULSE.

His date of joining submarines has not been established but, on 21 April 1941 he was appointed to the Submarine Depot Ship HMS MEDWAY at Alexandria and, on 24 August 1941 to HMS REGENT as Engineering Officer. HMS REGENT failed to return from patrol in Adriatic, possibly sunk by a mine off Monopoli about 1 May 1943 and was assumed to have been lost with all hands.

Edwin Pratt was the husband of Elsie May Pratt of Ryde, Isle of Wight and he is commemorated on the Portsmouth Naval Memorial on Panel No. 73 Column No. 1.