The aircraft carrier was initially ordered for construction by Britain's Royal Navy as HMS Powerful during the Second World War.

Following the end of the war, construction on the ship was halted and it was not until 1952 that work began once again, this time to an altered design for the Royal Canadian Navy.

The ship entered service in 1957 renamed Bonaventure and, until the vessel's decommissioning in 1970, was involved in major NATO fleet-at-sea patrols and naval exercises and participated in the Cuban Missile Crisis.

Powerful was purchased by the Royal Canadian Navy in 1952 and the hull was taken to the Harland & Wolff shipyard in Belfast, Northern Ireland, to be completed to a modernized design of the Majestic subclass.

[2] Bonaventure had a distinct appearance compared to her sister ships as she had a tall lattice mast, raked funnel and large sponson where the 3-inch guns were situated.

The Majestic subclass' design allowed for heavier aircraft, those up to 20,000 pounds (9,100 kg) landing at 87 knots (161 km/h; 100 mph), to be launched and recovered.

[2] The angled flight deck increased the carrier's landing area without limiting space for aircraft parking and allowed for the removal of antiquated crash barriers.

[10] Despite this, Bonaventure conducted sustained around-the-clock operations, keeping four Trackers and two HO4Ss in the air at all times, while monitoring an area of 200 square nautical miles (690 km2).

The ship's role then changed to one of pure ASW and the air wing was modified, dropping the fighters but keeping the eight Trackers, and increasing the number of HO4Ss to fourteen.

[14] The British government ordered a second hull constructed of what would become the Majestic class on 16 October 1942 once a dock opened at Harland & Wolff's shipyard in Belfast, Northern Ireland.

The aircraft carrier's keel was laid down on 21 November 1943 with the yard number 1229 and the British Admiralty chose the name Powerful for the ship.

[15] Work on Powerful resumed, this time to a modernized design incorporating recent carrier operation developments, such as the angled flight deck and steam catapults.

Construction was completed on 17 January 1957, and the vessel was commissioned into the Royal Canadian Navy at Belfast as HMCS Bonaventure with Captain H.V.

[12][19] In October, the aircraft carrier began further trials with her air group composed of VF 870 (Banshee), VS 881 (Tracker) and one HO4S helicopter in the Caribbean Sea that lasted until early 1958.

[12] On 2 October, a Banshee fighter flying from Bonaventure to the naval air base HMCS Shearwater was lost at sea.

[21] In November 1958, while operating off the Grand Banks of Newfoundland, Bonaventure and her escorts made contact with a Soviet Navy submarine while patrolling around a group of Russian fishing trawlers.

[7] In 1960, NATO reorganized their defence of the North Atlantic and the Canadian contribution to the new plan centred around an ASW hunter-killer group led by Bonaventure.

[23] The aircraft carrier rejoined the fleet in November 1960, embarking VF 870 (Banshee), VS 880 (Tracker) and HS 50 (HO4S) squadrons.

[12] On 13 October 1962, at the onset of the Cuban Missile Crisis, Bonaventure and the 1st Canadian Escort Squadron were sailing through United Kingdom territorial waters.

[7] That year Bonaventure took part in the Sharp Squall naval exercise and in September, participated in testing ASW defences in the Greenland-Iceland gap.

[12] The 1964 Navy estimates called for the major refit of Bonaventure in order to extend the aircraft carrier's service life.

While there, Bonaventure was recalled to Canada to embark troops from the Canadian Royal 22nd Regiment for service in a United Nations peacekeeping venture.

Called Operation Snow Goose, 95 soldiers, 54 vehicles and 400 tons of stores were loaded aboard the aircraft carrier and the ship disembarked them at Famagusta, Cyprus on 30 March.

The following year in January, Bonaventure, along with six escorts, took part in the largest Canadian naval activity in the Caribbean Sea and South American waters.

In April the ship was sent to recover Canadian forces from Narvik, Norway, after a military exercise and made a final visit to Portsmouth on the way back to Canada.

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.