Have the naval hydrofoils had their day? It’s hard not to think that the best flying is behind us, when we look at the glory days when HMCS Bras d’Or (FHE-400) wowed observers near Halifax, Nova Scotia, flying up on her foils at 62 knots, or 114.8 km/h. This wondrous burst of speed occurred 52 years ago today. For this post, the Shipsearcher staff historian takes a look at Canadian naval hydrofoils. A future post will provide a brief survey of other navies’ remaining hydrofoils.

Hydrofoils are a unique mix of aircraft and boat: “Foils” fitted to the lower hull of a vessel act in the water like wings do in the air. With speed and adjustment of the foils, lift is achieved, which raises the watercraft up, and allows it to become “foilborne” with the hull or main body of the craft flying over the surface of the water. When flying, there is very little water resistance to slow the craft down, and so hydrofoils can attain remarkable speeds, and can also be very stable during their flight.

The development of hydrofoil technology was an international effort. Canada played an important role in both the origins of the technology, and some of its milestones. Scottish/American inventor Alexander Graham Bell may be regarded as the founding father of naval hydrofoil technology. Hydrofoil experiments came out of his interest in aviation, where he and a small group were designing pioneering aircraft or “aerodrome” (Bell’s term) designs at the very beginnings of powered flight.

Experiments in designing floats for aircraft to become airborne from a water-start led to a passionate interest in achieving lift using wing-like foils in the water. Bell worked out of his estate and laboratory “Beinn Bhreagh” on the Bras d’Or Lakes of Cape Breton, Nova Scotia, in the first years of the 20th Century. He had been inspired by Italian inventor Enrico Forlanini’s earlier work building hydrofoil boats on Lake Maggiore, in Italy, and had travelled there in 1910 to see these craft. He and his associates, especially F.W. “Casey” Baldwin, collaborated on a whole series of experimental designs.

Each iteration of hydrodome overcame faults which had often destroyed the previous craft. During 1913, Bell and Baldwin got to work on a new design, “Hydrodome number 4” – HD-4 – that they hoped would correct previous design flaws, and lead to possible naval contracts. The First World War interrupted further work, as Bell’s Cape Breton boat-works were given over to wartime construction.

Work on HD-4 resumed at the conclusion of hostilities. The US Navy supplied the Liberty V-12 aircraft engines, and evaluated her in September, 1919. The HD-4 was a triumph for Bell and Baldwin, flying at 61.5 knots, or 114 km/h – a record-breaking speed. Two years later the Royal Canadian Navy (RCN) evaluated HD-4 for different purposes. No naval construction followed these projects. Casey Baldwin continued development of several more HD craft after Alexander Graham Bell’s death in August, 1922.


Development of a military hydrofoil project became a focus of Canadian government defence research after the Second World War. The RCN partnered with the Defence Research Board (DRB) to work on the Canadian Hydrofoil Project. A cadre of experts forming around the Naval Research Establishment in Halifax, NS. The team looked again at the designs of Bell and Baldwin, subsequent developments, and contemporary programs, such as US Navy hydrofoil designs. Canadian designs would focus on surface-piercing hydrofoil technology. A 45-foot boat, the Massawippi (R-100), was initially acquired in 1951. It helped develop the ladder style of foils used in subsequent designs.
Next came the Bras d’Or (R-103), built by British Saunders-Roe as a unique design. The hull tapered along its length, to a distinctive narrow transom, to give the rear foils room. The V-shaped ladder foils had not benefited from the same rigorous design experimentation as other aspects, and the craft struggled to become foil-borne on trials. Bras d’Or was shipped across the Atlantic in 1957 on the new RCN carrier, HMCS Bonaventure. In testing she eventually reached speeds of 30 knots, or 55 km/h.

Challenges encountered during the testing of R-103, and solutions for optimizing the foil configuration tested on the Rx, would continue to inform the design of the ultimate Canadian project: HMCS Bras d’Or (FHE-400). The new craft was a 160-foot long, 240 ton space-aged wonder. De Havilland Canada was selected as the prime contractor and the craft was built at Marine Industries Ltd., at Sorel Quebec, between 1963-1968.

Just about everything about the construction of this craft was innovative, from the aluminum hull-form (built upside-down in the shed at Sorel) and Pratt & Whitney gas turbine engines used in construction, to the advanced diamond shaped foils, forged from special maraging steel. The ship needed to be controlled by a qualified pilot, and the small wheelhouse looked more like the cockpit of a jetliner. Instead of rudders, the vessel’s steering was controlled by the unique rotating forward foil. Designers worried about the crew tasked with serving in this revolutionary craft, and effort was spent trying to develop comfortable quarters and sleeping arrangements, and, since a galley was out of the question, the ship was even fitted with the newly-developed microwave oven!

Unusual as it might sound today, Bras d’Or was intended to have been used in an open-ocean or Anti-Submarine Warfare (ASW) role, with the navy also experimenting with a special light and compact Variable Depth Sonar outfit: the SQS-507. The armament would have featured two sets of triple torpedo tubes. It was hoped that a small fleet of hydrofoils would replace the aging, wartime-built fleet of frigates then leaving service, and be significantly less expensive than the RCN’s “Cadillac” destroyer-escorts. The concept of the ASW hydrofoil was that it would patrol in hull-borne mode up to a respectable speed of 23 knots, using regular marine diesels. Bras d’Or was fitted with Paxman diesel engines. Upon establishing a sonar contact, the ship would dash to close proximity using the extraordinary foil-borne speed, before reacquiring the contact and attacking. After lengthy development and a fire that set back construction, Bras d’Or was ready for commissioning in July 1968 (the smaller R-103 was renamed Baddeck to leave the name free for its bigger successor).

Testing in the waters near Halifax showed her exceptional stability when flying, even in heavy seas. On 9 July 1969, Bras d’Or flew at speeds of up to 62 knots (114 km/h). As far as we know, this still makes her the fastest commissioned warship.* Unfortunately, changing government defence priorities resulted in the hydrofoil project being set aside. HMCS Bras d’Or was decommissioning in November 1971, and this coincided with an end to further Canadian military hydrofoil development. The costs of the program no longer looked likely to provide the RCN with a fleet of “cheap” ASW hydrofoils, and many of the technologies, such as the special sonar and the armament for the ship, had yet to be fully developed, and may have led to more costly programs. As a concept, the ASW hydrofoil was an evolutionary dead-end. Internationally, the development of military hydrofoils continued to focus on high-speed coastal patrol, torpedo boats, and fast-attack craft (gun and missile-armed).

Today, we are fortunate to have relics of the era when Canada was at the cutting edge of hydrofoil development. HMCS Bras d’Or survives out of the water at the Musée Maritime du Québec, at Islet, QC.

Baddeck (the former Bras d’Or) is in storage at the Canadian Museum of Science and Technology in Ottawa, Ontario. After a long period of outside storage, the partially-disassembled boat rests inside a new state-of-the-art preservation facility, and, we hope, will be reunited with its preserved foils.



Massawippi (R-100) appears to have survived, after her 1959 decommissioning, at either at the Nova Scotia Museum or the Maritime Museum of the Atlantic (possibly at a storage facility in Mount Uniacke, NS). Canadian Aviation Historical Society member Kyle Huth let us know about the survival of this boat, while we also located some information about historian Thomas Lynch’s attempts to locate R-100, which can be found at the International Hydrofoil Society’s website. Alexander Graham Bell’s HD-4 Hydrodome also partially survives in Baddeck, NS, at the Alexander Graham Bell Museum, near a full-scale replica. A future post will pick up the story by examining international naval hydrofoil development and other surviving craft.

Additional Shipsearcher and other resources:
Views of the Baddeck (R-103) and HMCS Bras d’Or (FHE-400) are located in the listing for RCN auxiliaries and other ships.
For a detailed account of both Alexander Graham Bell and Casey Baldwin’s work, as well as the subsequent RCN projects, see John Boileau’s Fastest in the World; the Saga of Canada’s Revolutionary Hydrofoils (Halifax: Formac Publishing Co. 2004).
A Canadian War Museum short exploration of HMCS Bras d’Or: https://www.warmuseum.ca/cwm/exhibitions/navy/galery-e.aspx@section=2-G-2&id=3&page=0.html
Renald Fortier, curator of the Canadian Aviation and Space Museum discusses the evolution of hydrofoil technology: https://ingeniumcanada.org/channel/articles/and-now-for-something-completely-different-a-flying-ship-from-toronto-ontario
Marcelle Cinq-Mars, Military Archivist at Library and Archives Canada, notes the arrival of a new collection of Hydrofoil-related records transferred to LAC from the Defence Research Establishment, Atlantic. https://thediscoverblog.com/2018/06/26/a-unique-example-of-canadian-research-hmcs-bras-dor/
There are several articles on the hydrofoil project in the editions of Crowsnest, the RCN’s magazine. 1949-1965 editions have been digitized on the publications.gc.ca website: https://publications.gc.ca/site/eng/9.880827/publication.html
Dave Mills’ website gives a detailed account of the R-103 Bras d’Or / Baddeck, with lots of visuals, including of her current condition: http://dave-mills.yolasite.com/saro-hydrofoil-bras-dor.php
* The fastest armed warships, currently, are the Skjold class missile catamarans, which also use Pratt & Whitney of Canada engines to attain speeds of up to 60 knots, or 111 km/h