John Coombe was born in 1915, the son of Robert Gorton Coombe (a planter) in Ceylon (now Sri Lanka) and Dorothy Augusta Coombe (née Goolden).

He joined the Royal Navy as a Cadet on 3 September 1932 and was appointed to the battleship HMS NELSON. He was promoted to Midshipman on 1 May 1933 and, on 1 July 1933, was appointed to the cruiser HMS HAWKINS. Midshipman John Coombe was next appointed to the cruiser HMS EMERALD in October 1934.

On 26 September 1935 he was appointed to the Royal Naval College, Greenwich to take his Lieutenant’s Courses and, on completion he was promoted to Sub Lieutenant on 16 May 1936. He joined submarines in 1937, was appointed to HMS SHARK on 7 July 1937 and was promoted to Lieutenant on 16 May 1938.

He was married to Miss Amber Bettine Gardner in the church at Felpham, Sussex on 4 March 1940.

John Coombe was appointed to HMS PORPOISE as First Lieutenant in August 1940. He took his Commanding Officers Qualifying Course from 30 June 1941 and then served in HMS H32 in command from 3 September to 6 December 1941. He then joined HMS UPRIGHT in command, as temporary relief for Lieutenant Wraith, for a war patrol from 9 to 23 February1942.

On 23 February 1942 he was appointed to HMS TALBOT (the submarine base at Malta) and then appointed to HMS UTMOST in command on 16 September 1942. John Coombe died on 25 November 1942, on his sixth war patrol in UTMOST. when the submarine was lost with all hands. It was thought that UTMOST had been sunk in a depth charge attack by the Italian Torpedo Boat Groppo, but further research suggests she was mined whilst returning to Malta.

John Coombe is commemorated on the Portsmouth Naval Memorial on Panel 62, Column 1.