HMS Bonaventure was a submarine depot ship of the Royal Navy. She was initially built for civilian service with the Clan Line, but on the outbreak of the Second World War she was requisitioned by the Navy and after being launched, was converted for military service. Career Construction and commissioning The ship was laid down at the yards of the Greenock & Grangemouth Dockyard Company, of Greenock, Scotland as a Clan Line . She was provisionally allocated the name Clan Campbell. With the outbreak of war, Admiralty requisitioned her for the Royal Navy, and after her launch on 27 October 1942, she was converted at the yards of Scotts Shipbuilding and Engineering Company to become a submarine depot ship for the midget submarines. After the conversion was completed she was commissioned into the Navy on 26 January 1943. Early wartime service After completing work-up trials, Bonaventure sailed to Loch Striven on the west bank of the Clyde to become the main training base and depot ship for the X craft midget submarines. In August and September 1943, training and trials were carried out for the midget submarines , , , , and . They were to be used to carry out the attack on the in Altenfjord, Norway, codenamed Operation Source. During the operation, the submarines , , , , and each towed a midget submarine to Norwegian waters. Despite a number of the X craft being lost, the operation was a success and Tirpitz was put out of action for six months. In October Bonaventure sailed to Govan to be refitted at the yards of Alexander Stephen and Sons. The refit took until 2 January 1944 and included fitting new radar equipment. Some work was not completed before Bonaventure was recommissioned on 22 January to serve with the British Pacific Fleet. She again deployed at Loch Striven in preparation. She remained deployed there until March, when she returned to Govan to complete the outstanding dockyard work. The refit lasted until August, when after post-refit trials, she returned to Loch Striven in September. October to November was spent training on the loch. During this period, the modified s, which had been under construction since January 1944, became available. Several were embarked aboard Bonaventure for use against targets in the Far East. In December she was nominated for deployment as the depot ship for the 14th Submarine Flotilla in the south