HMCS Bonaventure (CVL 22) was a Majestic-class aircraft carrier that served in the Royal Canadian Navy and the successor Canadian Forces Maritime Command from 1957 to 1970 and was the third and the last aircraft carrier to serve Canada's military. The ship was laid down for the British Royal Navy as HMS Powerful in November 1943 but work was suspended in 1946 following the end of the Second World War. At the time of purchase, the Canadian Navy made it a requirement that new aircraft carrier technologies be incorporated into the design. Bonaventure never saw combat during her career, however, she was involved in major NATO fleet-at-sea patrol during the Cuban Missile Crisis.
As HMS Powerful she was laid down at Harland and Wolff in Belfast on 21 November 1943, and launched on 27 February 1945. Work was suspended following the end of the Second World War, and only resumed when it was bought by the Royal Canadian Navy in the early 1950s, which was looking to replace the Second World War–era light carrier HMCS Magnificent (another Majestic-class carrier), which had some deficiencies including not being able to operate newer jet age aircraft. Both the United States and Great Britain offered carriers for consideration and the incomplete HMS Powerful, a Majestic-class light fleet carrier, was purchased in 1952 from the Royal Navy on the condition that it be fitted with an angled flight deck, steam catapults and an optical landing system.
Bonaventure was named for Bonaventure Island, a bird sanctuary in the Gulf of St. Lawrence and was commissioned with the requested improvements into the Canadian Navy on 17 January 1957. In 1966 the carrier began a mid-life refit in Quebec City which took 18 months and cost $11 million, both behind schedule and well over budget. Following the 1968 Unification of the Canadian Forces, and budget cuts, Bonaventure was decommissioned in Halifax, on 3 July 1970, and was scrapped in Taiwan in 1971. Components from Bonaventure's steam catapult were used to rebuild the catapult aboard Australian aircraft carrier HMAS Melbourne, another Majestic-class carrier.
Bonaventure's primary role was in anti-submarine warfare, protecting Canada's maritime trade, primarily in the Atlantic and helping Canada meets its NATO commitments. In addition, its Banshees contributed to Canada's air defences. During the 1962 Cuban missile crisis, Bonaventure operated alongside US Navy carriers as a part of the blockade. In 1964, Bonaventure was also used as an equipment ferry, taking troops and their gear, including 54 vehicles and 160 tons of equipment, to Cyprus for the Canadian peacekeeping mission there.
During its service life, Bonaventure carried five squadrons. Initially, she embarked 34 fixed wing aircraft and helicopters, however this had been reduced to just 21 aircraft by 1967. The McDonnell Banshee fighter, flown by VF 870 and VF 871 Squadrons, and the Grumman CS2F Tracker anti-submarine warfare (ASW) aircraft operated by VS 880 and VS 881 Squadrons were flown from Bonaventure, along with Sikorsky HO4S ASW helicopters operated by HS 50 Squadron.
Even with the angled deck, Bonaventure's flight deck was short for the Banshees and some US Navy pilots refused to land on her deck. The long-span Trackers were also a tight fit. Despite this, Bonaventure conducted sustained around-the-clock operations, keeping four Trackers and two HO4Ss in the air at all times, which monitoring an area of 200 square nautical miles (690 km2). The Banshees were retired in 1962 but were not replaced, and in 1964 Sikorsky CHSS-2 Sea King helicopters began replacing the HO4S. When Bonaventure was retired, her former aircraft continued to operate from shore installations, including CFB Shearwater.
Bonaventure had two ships' anchors. Her starboard anchor, donated by Maritime Command 6 May 1998, is on display at Royal Military College Saint-Jean. The second ship's anchor is preserved at Point Pleasant Park in Halifax where it serves as a monument to the men and women who died while serving the Canadian Navy during peacetime. The ship's bell is preserved at the Shearwater Aviation Museum in Dartmouth, Nova Scotia which also hosts a large model and exhibit about the carrier.