Harold Cook was born in Rochford in Essex on 14 February 1918, the son of Herbert and Edith Millicent Cook of Leigh on Sea, Essex.

He joined the Royal Navy Volunteer Reserve as a Temporary Sub Lieutenant on 6 March 1941. He served in the corvette HMS AMARANTHUS from 6 April 1942 and then joined HMS DOLPHIN ‘for Motor Launches and Miscellaneous Duties’ on 22 May 1942. Having volunteered for ‘Special Service’ he was appointed to the Submarine Depot Ship HMS TITANIA on 12 June 1942. He then trained as a Charioteer No. 1 Crewman at HMS VARBEL. He was promoted to Temporary Lieutenant RNVR on 1 December 1942. After his training he was selected for Operation PRINCIPLE – an attack on Italian shipping at Palermo.

He was the No. 1 Crewman of one of three chariots launched from HMS TROOPER on 2 January 1943.  Of the ten charioteers launched in this operation, he and one other did not survive.

Harold Cook had accidentally ripped his suit on a net and was suffering from severe seasickness. His No 2 Crewman, Able Seaman Worthy, drove the craft ashore to leave Cook in a place of safety and carry on alone, but he found the craft too difficult to handle alone and abandoned it in deep water. He swam back to where he had left Cook but failed to find him. Worthy was taken prisoner. It is not clear what happened to Cook – was assumed to have drowned on 2 January 1943.

He is commemorated on the Portsmouth Naval Memorial, Panel 80 Column 1 and on the 12th Submarine Flotilla memorials at Rothesay on the Isle of Bute and at Kylesku.