So Long Bonnie: Canada’s role in Anti-Submarine Warfare, Part I

by | Jan 11, 2019 | LCSC, War and Society | 0 comments

So Long Bonnie: The Decommissioning of HMCS Bonaventure and Canada’s role in Anti-Submarine Warfare

By Hugh A. Gordon, Keyano College

Part I: Origins and a Missed Opportunity

This is the first in a series of articles about the decommissioning of the HMCS Bonaventure. 


If you ask any Canadian naval aviation veteran, September 19, 1969 was a dark day for Maritime Command of the Canadian Armed Forces (CAF). On that date, Minister of National Defence Léo Cadieux announced massive cuts to the CAF as part of an ongoing Defence Policy Review, but more importantly for naval observers, he also revealed the decision to decommission Canada’s third and final aircraft carrier, HMCS Bonaventure. The carrier had served Canada since 1957 in an anti-submarinewarfare (ASW) role. To this day, Canada’s naval aviators insist that Bonaventure was the best anti-submarine tool Maritime Command had, and that the government just threw it on the scrapheap. The truth is rather different. While the decision was ostensibly made for politically attractive financial reasons, an examination of military records shows that the decision had a strategic rationale.


Bonaventure was “laid down” in shipbuilding parlance in 1945 at the Harland and Wolff shipyards in Belfast, Northern Ireland, and was to be built for the British Royal Navy (RN) as HMS Powerful. The end of the Second World War halted construction and the hull was left partially built until 1952 when Canada sought a carrier of its own to replace HMCS Magnificent, which itself was on loan from the RN. Entering service in 1957, initially with McDonnell F2H-3 Banshees, Grumman CS2F Trackers, and Sikorsky HO4S helicopters, the Bonnie, as the carrier was affectionately known, was used primarily for ASW. The goal of the Bonaventure in a potential war was to detect, track, and destroy Soviet and Warsaw Pact submarines before they could either attack NATO shipping or launch ballistic missiles at civilian targets. In 1962, the helicopters were replaced with the now infamous Sikorsky CHSS-2 (CH-124) Sea Kings, which are still in use today and about to be replaced, but the Banshees were retired without replacement as more modern jets were too big for Bonaventure’s short flight deck.

Shipbuilding in Belfast, Northern Ireland, November 1944. A28022

The Bonnie was, and remains, the largest ship to have served in the Canadian Navy. The ship used a fifth of the Navy’s manpower, enough to staff four destroyers, and cost twenty million dollars a year to maintain, which would be 134 million in 2017 Canadian funds.[i] To the ship’s defenders, this usage of manpower and money was justified in order to have the ASW capacity the carrier brought to the Navy. To the ship’s detractors, this spending was simply too much. Maritime Command’s limited resources needed to be used more widely during a time when government confidence in that branch of the service was low. The controversial “Unification” of the CAF had occurred less than five years earlier. The Navy had been the most critical opponent of the reorganization and, as a result, many of its senior officers were no longer in place in 1969. No actively serving naval officers protested the decommissioning of the carrier, which would not have been the case just a few years earlier.

The ship’s public detractors were indeed many, and its defenders, few. Famous officers of other service branches questioned the need for the carrier in government investigations. Academics and journalists used public forums to criticize the Bonaventure’s capabilities. Finally, Department of National Defence (DND) analysts themselves were rethinking the need for the carrier because of strategic limitations. With the continuing changes and improvements in Cold War navies, Bonaventure was lacking in several areas. When the Banshees had been retired, the ship was left without effective anti-aircraft (AA) defences. The ship was also slower than other NATO units with which it served, which was another vulnerability.[ii] Defence analysts assumed, erroneously as it turned out, that Soviet nuclear fleet ballistic missile submarines (SSBNs) would become faster and stealthier beyond Bonaventure’s capacity to detect, locate, and destroy them.

The carrier’s shortcomings did not simply come into focus at the end of its career. There were discordant voices that questioned the need for the carrier as early as 1960. An article in Star Weekly magazine by science editor Leonard Bertin questioned the RCN’s mix of ships and equipment. While insisting the officers and men were superb, he argued that Canada had not spent enough money on its defence. Instead of an aircraft carrier with fixed wing aircraft, he argued that the Navy should have spent more money on nuclear attack submarines (SSNs) that could easily follow and detect Soviet SSBNs. Bertin agreed that helicopters in ASW had their uses. Otherwise, his concerns about the carrier were in the minority at this time. The carrier, which had only been commissioned three years earlier, had not yet been tested to the extent of its capabilities. The first chance Bonnie had to prove its worth was the Cuban Missile Crisis.[iii]

In October of 1962, the United States revealed it had discovered the installation of Soviet ballistic missiles in Cuba. What followed was perhaps the most dangerous period of the Cold War as the Americans established a naval blockade, or “quarantine”, of Cuba in order to force the Soviet Union to withdraw its missiles from that nation. As part of the military build-up, the Soviets had sent a few submarines equipped with nuclear-tipped torpedoes to Cuba. These subs had no safeguards that could have prevented a Captain from launching a torpedo at a NATO fleet and possibly launching World War III.

This was a perfect time for Canada to show that Bonaventure was a prime ASW tool. Unfortunately, the political climate between the United States and Canada limited involvement by the RCN in operations during the Crisis. Prime Minister John Diefenbaker and American President John F. Kennedy had abysmal relations with one another, and the countries’ interactions suffered as a result. Officially, the Canadian Navy was not given orders to aid the Americans in the attempt to prevent Soviet submarines from sneaking past NATO forces undetected. However, as Peter Haydon has pointed out, the RCN continued to aid the USN. Even though Canada’s military leaders were disregarding the chain of command, this was the perfect crisis for Bonaventure and her crew to prove their worth. Unfortunately, for unknown reasons, the Bonnie was told to come home from European waters at economical speed. The carrier arrived back on the East Coast of Canada the same day that the Soviet government announced they were dismantling the missiles in Cuba. The crisis was effectively over by that point, but some submarines had not yet been located. Haydon suggests that Bonaventure was helpful in restoring sea supremacy for NATO, but the fact that the carrier was not where it needed to be during the crisis ensured that it never proved its worth in such a situation. This missed opportunity to prove that Bonaventure could do its job seems to suggest that Canada’s military forces were only for show in the Cold War. The only real protection Canada had against Soviet submarines and ballistic missiles was the deterrence provided by the American nuclear umbrella. However, there could also have been practical reasons why Bonnie was not sent home at top speed. There might not have been enough fuel available, or there could have been a realization that with the crisis unfolding so quickly, Bonaventure might not have made it back to Canadian waters in sufficient time to be of any help locating Soviet submarines. Its route back to Canada would have also allowed it to search and locate subs in the mid-Atlantic.[iv] The HMCS Bonaventure would have no other chance to prove it was an effective ASW tool.

[i] “Bonaventure’s annual bill of $20 million was just too high”, Globe and Mail, 20 September 1969, 12;

Bank of Canada, “Inflation Calculator”,, accessed on 5 May 2017.

[ii] James Eayrs, “Bonaventure’s Career: HMCS White Elephant,” Montreal Star, 29 September, 1969

[iii] Leonard Bertin, “Canada Hasn’t Got the Right Kind of Navy,” Star Weekly Magazine, 27 February 1960.

[iv] Peter Haydon, The 1962 Cuban Missile Crisis: Canadian Involvement Reconsidered (Toronto: The Canadian Institute of Strategic Studies, 1993), 146.