Hythe’s Flying Boat History (+ BOAC Flying Boat Wartime Operations)

Hythe in Hampshire has a rich marine aviation history, from the establishment of a site on Shore Road in 1917 by the British Admiralty for military production of flying boats to Supermarine and Imperial Airways’ presence, then World War II, with BOAC’s role and the subsequent termination of flying boat operations in 1950, then the site becoming RAF Hythe. Researched and written by Martin Halliday.

Hythe’s flying boat heritage can be traced back to 1917 when the British Admiralty acquired Winterton Hall, and land located on Shore Road, to establish a facility for the production of military flying boats. John Mowlem & Co were employed to demolish Winterton Hall and to construct, under the design of notable HM Office of Works architect Sir Frank Baines, a large flying boat production building of some 7,000 square metres, with a concrete apron and a slipway into Southampton Water.

Whilst there would be a number of additions and changes over the years, the structure of the original building with its distinctive sawtooth roof design remains to this day; is considered to be an unique example of a flying boat production facility and is still referred to by some local residents as the ‘Admiralty Sheds’.

seen from hythe marina
The distinctive sawtooth roof of original Flying Boat building as seen today from Hythe Marina

Flying Boats would be directly associated with Hythe for over three decades. With the cessation of commercial flying boat operations in 1950, the site became HMS Diligence (1953 to 1963) and was used for the fitting out, maintenance and storage of Minesweepers. From 1967 to September 2006, the site was re-designated as RAF Hythe and was used by the US Field Support Battalion (employing some 210 British nationals at its peak) for the maintenance, storage and support of forward-deployed US Army watercraft.

The original flying boat building is grade 2 listed, and is now home to Hythe Marine Park.

hythe marine park
Hythe Marine Park 2007 Exhibition Brochure with original Flying Boat building (bottom left of picture)

WW1 Flying Boat Production in Hythe

In early 1900s, Morgan Giles and May owned the shipyard at Hythe. In 1915, they formed the company May, Harden, and May, as a subsidiary of The Aircraft Manufacturing Company Limited (trading as ‘Airco’), which had secured a contract to produce Felixstowe military flying boats.

During 1917 to 1918, May, Harden, and May manufactured at Hythe, under the Airco contract, some seventy one Felixstowe flying boats for use by the Royal Naval Air Service. Once this contract was finished, Airco became unprofitable and in 1920 the Company was sold then liquidated.

Felixstowe F5 flying boats
Felixstowe F5 flying boats in flight in 1919.

Post WW1, the Admiralty made a number of unsuccessful attempts to sell the vacant site.

Supermarine in Hythe

In 1925, Supermarine of Southampton acquired the Hythe flying boat site, as an additional facility to its main Woolston works, for the production and/or assembly of Supermarine’s ‘Southampton’ military flying boats (designed by RJ Mitchell) for use by the Royal Air Force.

Supermarine Southampton flying boats
Supermarine Southampton flying boats.

In 1928, Vickers-Armstrong took over Supermarine and the Company continued to use Hythe for the production and/or assembly of its developing range of both military and commercial flying boats including the Seagull, the Stranraer and the Walrus.

However, by the late 1930s, the use of the Hythe site by Vickers Supermarine had significantly reduced.

Imperial Airways in Hythe

Imperial Airways had been formed by the British Government in March 1924 with a view to creating Britain’s first national air service.

Imperial Airways was granted British Government approval for the establishment of an air service across the British Empire. From 1929 onwards, it trialled and established routes to India, Singapore and, by 1934, to Australia (under a flight share arrangement with Qantas).

To support and expand the Empire service, given the lack of aerodromes at the time, Imperial Airways looked to Short Brothers of Rochester to develop and produce a fleet of flying boats.

In December 1934, the British Government sanctioned a proposal from Imperial Airways for the creation of an Empire Air Mail Service.

Imperial Airways placed an order for a number of Empire C Class S 23 flying boats that had been developed by Short Brothers.

G-ADHL Canopus
Construction of the first Empire C Class S23 flying boat G-ADHL Canopus during July 1936 by Short Brothers at their Rochester factory at a cost of £37,800. Canopus was used for flight testing to prove airworthiness (of the Empire C Class S23 flying boat) and, from October 1936, undertook trials and proving flights based mainly in the Mediterranean. Canopus arrived in Hythe in March 1937 for full servicing and repairs. Photo supplied by Mike Phipp, author of ‘Flying Boats of the Solent and Poole’ book pub. 2013.

In line with the tradition of naming luxury ships, each Empire C Class flying boat would be built under a name commencing with the letter ‘C’. The Empire flying boats could accommodate 24 seated passengers or 16 in a sleeping berth layout. With its promenade deck, Imperial Airways would ultimately advertise their new flying boat passenger service as “most effortless and luxurious travel the world has ever seen”.

passenger cabin
Imperial Airways Empire C Class S23 flying boat passenger cabin with ‘luxury’ level seating. Photo supplied by Mike Phipp, author of ‘Flying Boats of the Solent and Poole’ book pub. 2013.

Seeking a base that would be able to accommodate an anticipated fleet of flying boats, Imperial Airways reached an agreement with Vickers Supermarine to lease part of the Hythe flying boat facility.

On 4 December 1936, Imperial Airways flying boat Caledonia landed on Southampton Water – the first Empire C Class S 23 flying boat to be delivered by Short Brothers to Hythe. Caledonia was followed by Cambria on 21 January 1937; both would be used to undertake trials of long distance flying boat routes.

The first flight of Imperial Airways’ Empire Air Service took place with Castor departing Southampton Water on 8 February 1937 for Alexandria, Egypt.

The Imperial Airways Hythe flying boat base was officially opened on 5 March 1937; Empire class flying boat arrivals and departures would be served by a temporary terminal at Berth 101 in Southampton Docks.

Flying Boats Hythe
Aerial photograph of Imperial Airways Flying Boat Servicing and Maintenance Base at Shore Road, Hythe c. 1937 with Imperial Airways Flying Boats on the apron and a Flying Boat on the slipway.

The Empire Air Mail Programme was inaugurated when Centurion departed Southampton Water on 29 June 1937. All letters were charged at a flat rate 1.5d (old pence) per ounce irrespective of destination.

During July 1937, Imperial Airways published a timetable covering regular flying boat services from Southampton to Egypt, Iraq, Malaya, Hong Kong, and Australia.

Imperial Airways Capella flying boat Hythe
Imperial Airways Capella flying boat at Hythe circa 1937.

July 1937 also saw the first trial transatlantic crossing by an Imperial Airways Empire C Class S 23 flying boat. Caledonia departed it’s Hythe base for Foynes, Ireland on 5 July 1937; achieving its 15 hour non-stop transatlantic crossing from Foynes to Botwood, Newfoundland on 6 July 1937. Caledonia then flew on to New York where the crew were entertained by Pan-American Airways and given a tour of the Empire State Building.

Imperial Airways Caledonia safely arrives in Botwood, Newfoundland 6 July 1937 following her maiden transatlantic flight. Photo courtesy of  Botwood Heritage Society

Under a reciprocal arrangement with Pan-American Airways, a Pan-Am Clipper III flying boat arrived at Southampton Water from Foynes on 8 July 1937. The Pan-Am crew were officially welcomed by the Director General of Civil Aviation and by the Mayor of Southampton. With the Pan-Am Clipper flying boat having been serviced at Hythe, the crew (who had been staying at the Langdown Lawn Hotel in Hythe) took the Hythe Pier train on 14 July 1937 to board a launch to take them to the Clipper for its return transatlantic flight.

Caledonia had commenced its return journey landing at Southampton Water on schedule at 11am on Saturday 17 July 1937 to a chorus of sirens from ships on Southampton Water and in the Docks; the crew were officially received by the Managing Director of Imperial Airways.  

Whilst these flights and subsequent trial flights had proved transatlantic flying boat journeys were possible, it became clear that the S 23 flying boat did not have the required capability for a regular transatlantic service.

A new Imperial Airways departure and arrival terminal was established in Southampton Docks at Berth 108 in 1938.

By the end of 1938, a total of 27 Empire C Class S 23 flying boats had been delivered to Imperial Airways’ Hythe flying boat base. Due to its original design, the Hythe flying boat base could accommodate the servicing of up to 6 Empire flying boats at any one time.

By late 1938, Short Brothers had developed a more advanced variant of the Empire C Class flying boat – the S 30, with Champion being delivered to Hythe in October 1938, followed by Connemara and Clyde in March 1939.

In July 1939, Cabot & Caribou arrived at Hythe – these Empire C Class S 30 flying boats being adapted by Short Brothers to be capable of in-flight refuelling such that they would be able to meet the passenger and payload demands for Imperial Airways proposed transatlantic routes.

On 5 August 1939, Caribou took off from Southampton Water with a payload of 961 pounds of mail (comprising nearly 32,000 letters and packets) for Foynes, Ireland. During the transatlantic leg, she was refuelled in-flight Mid-Atlantic with 840 gallons of petrol from an air tanker before arriving in Botwood, Newfoundland and then onward to Montreal before arriving in New York on 6 August 1939 – a total journey time of just over thirty six hours with an actual flying time of just over 31 hours. Caribou would complete the return journey (with in-flight refuelling taking place Mid-Atlantic after departing Botwood) in a flying time (New York to Southampton) of under twenty two hours.

Short S30 Empire Flying Boat
Imperial Airways Short S30 Empire Flying Boat, G-AFCV, Caribou.

Pan-American Airways had continued their transatlantic flights; the Imperial Airways Hythe base servicing the American flying boats before their return across the Atlantic.

The pioneering days of Imperial Airways flying boat flights had not been without risk. Capricornus became lost in a snow storm over central France and crashed into mountains in March 1937 resulting in the death of six crew. Cygnus suffered a take-off accident at Brindisi in December 1937 with two crew members’ losing their lives. Five more Imperial Airways Empire flying boats would suffer lose: Courtier (October 1937, Athens), Calpurnia (November 1938, Iraq), Cavalier (January 1939, New York to Bermuda route), Challenger (May 1939, Mozambique) and Centurion (June 1939, Calcutta).  

Sadly, the Imperial Airways’ Hythe flying boats base would experience its own tragedy in June 1939 when Connemara was being refuelled from a barge off-shore at Hythe. A fire occurred costing the live of a Shell-Max employee (as well as the destruction of the flying boat) with another man suffering serious burns.

Imperial Airways flying boat operations were brought to an abrupt end with the threat of a world war. On 1 September 1939, to mitigate the prospect of bombing, Imperial Airways commenced the transfer of flying boat operations from Southampton to Poole.

BOAC flying operations during WW2

At the outbreak of WW2, all airline operations were brought under the control of the Secretary of State for Air. As a result, on 1 April 1940, Imperial Airways and its fleet of flying boats became part of a new national airline British Overseas Airways Corporation (BOAC).  

Some of the ex-Imperial flying boats, now based at Poole, assisted with supplying the British troops in northern France until the French surrender in June 1940. Caribou and Cabot were refitted as RAF Transport Aircraft and delivered to Norway but were destroyed in early May 1940 by a Luftwaffe attack.

With the end of the Phoney War stage of WW2, routes over Europe were no longer viable. To service the Empire, some of the BOAC flying boats operated the ‘Horseshoe Route’; based in Durban the route would involve flying up the East Coast of Africa to Egypt, then eastwards to Karachi, Singapore and down to Sydney (the latter leg using Qantas Empire flying boats).

BOAC flying boats also undertook a number of notable missions. On 20 June 1940, Cathay flew to Biscarosse (near Bordeaux) in France to evacuate General Sikorski, leader of the Free Polish force, successfully returning the next day at Poole. On 24 June 1940, Clyde left Poole for Lisbon carrying the Duke of Kent to attend Portugal’s 800th Anniversary celebration with Clare flying to Lisbon on 5 July 1940 to collect the Duke and returned safely to Poole.

On 5 August 1940, Clyde also took Free French VIPs to Leopoldville (now Kinshasa) in the Belgium Congo where the VIPs negotiated with a French Equatorial Delegation persuading them to switch their support from the Vichy French to the Allies allowing Allied Aircraft to open up a vital supply route from the Gold Coast across Central Africa to Khartoum.

Clyde and Clare were used as war-time propaganda flights during October 1940 by completing transatlantic flights (via Foynes, Ireland to Botwood, Newfoundland) to Montreal and New York carrying ‘official’ passengers with return via the same route.

A number of surplus ex-Imperial Airways flying boats were flown to Pembroke Dock where Short’s converted them for mainly RAF transport duties.

Flying boats that stayed in Poole, initially to operate a shuttle service to Lisbon and to Foynes (for connection to Pan Am transatlantic flying boats) were serviced and maintained at Hythe due to a lack of facilities in Poole.

Consolidated Catalina flying boats were acquired by BOAC to support the now ageing Empire flying boats. In May 1941, BOAC also purchased three Boeing 314 flying boats that were surplus to Pan-Am requirements; capable of long range, they were used mainly for transatlantic crossings (in winter via West Indies to US, in summer Foynes to Newfoundland to US).

On 15 January 1942, BOAC Boeing 314 ‘Berwick’ flew from Virginia, USA for Bermuda with Winston Churchill on board. Churchill had sailed in December 1941 to meet with President Roosevelt in Washington following the Japanese attack on Peal Harbour & the US entry into the War. Churchill was an amateur pilot; famously, he was allowed to pilot the flying boat for a time under supervision of the flying boat’s captain. Departing Bermuda, Berwick would safely deliver Churchill back to Britain arriving at Plymouth on 17 January 1942.

Churchill flying BOAC Berwick
Winston Churchill piloting BOAC Berwick flying boat in 1942

On 20 August 1943, Berwick flew from Canada (with fighter escort for its final leg of the journey) with Lord Mountbatten and other senior military brass on board returning to Britain for talks on the preparation for Operation Overlord.

During 1943, 6 Short Sunderland military flying boats were supplied to BOAC to extend its African services and routes.

To facilitate D Day operations, between May 1944 and September 1944, BOAC temporarily moved from Poole to Pembroke Docks.

During the War years, apart from servicing and maintaining BOAC flying boats, the Hythe flying boat base was also used to repair, modify and maintain four acquired Heinkel 115s (seaplanes) that were used (under RAF fighter escort) to take SOE operatives and agents in and out of occupied Europe.

WW2 would take its toll on the C Class Empire flying boats that had been built pre-war by Short Brothers; twelve would be destroyed in total during wartime as a result of operational crashes and accidents or through enemy actions.

Post WW2 BOAC Flying Boat Operations and the BOAC Hythe Class Flying Boat

As WW2 drew to a close, BOAC started to look forward to peace time operations and a return to Southampton as its operational base. However, it would not be until April 1948 that Southampton could accommodate flying boat departures and arrivals when a new flying boat terminal was opened in Southampton docks at Berth 50. BOAC’s aim was to supply luxury travel and it re-instated a full schedule from Southampton across the World as far as New Zealand and Australia.

BOAC Southampton
BOAC Flying Boat Terminal and Berthing Pontoons at Berth 50 Southampton Docks (in the foreground of the photo) with a BOAC flying boat berthed on the left-hand pontoon and a further BOAC flying boat moored near the right-hand pontoon. Queen Elizabeth occupies the Ocean Terminal (in the centre of the photo). Photo supplied by Mike Phipp, author of ‘Flying Boats of the Solent and Poole’ book pub. 2013.

In addition to the maintenance and servicing of BOAC flying boats, the Hythe site would once again be involved in the production of flying boats. Post war, twenty two Short Sunderland Mk III flying boats were converted to civilian use at the Hythe flying boat base. The first such conversion actually took place at Hythe in Spring 1945 during which basic soundproofing, seats and a galley were installed facilitating a passenger capacity of twenty two plus crew and mail payload. The forward gun turret was replaced by a fairing located within the body of the nose section giving the aircraft its distinctive nose section profile.

These conversations were appropriately given the class name Hythe and in line with flying boat tradition each converted Hythe received an individual name starting with ‘H’ – examples being the Hythe class Hampshire flying boat and the Hythe class Hamble flying boat.

BOAC Hythe Class Henley Flying Boat
BOAC Hythe Class Henley Flying Boat at Berth 50 in Southampton.

BOAC Hythe flying boats flew all over the world (as far as Australia). Hythe flying boats remained in service with BOAC until 16 February 1949 with Honduras completing the final return BOAC Hythe flying boat class flight arriving at Southampton from Sydney.

In addition to the Hythe class flying boat, post-war the main BOAC flying boat fleet comprised Sandringham class (ex-military Sunderland flying boats converted to a higher specification by Shorts) and a number of unconverted Sunderlands; three Boeing 314s (sold April 1948); and, subsequently, Short Solents (as replacement for retiring flying boats).

boac short solent flying boat hythe
BOAC G-AHIS Solent ‘Scapa’ flying over the BOAC Hythe Flying Boat Servicing and Maintenance Base in 1949.

The Hythe base had been expanded in the spring of 1947 to accommodate the expanded BOAC flying boat fleet. BOAC also used The Grove Building in St John’s Street, Hythe post war as an administration office.

The surviving ex-Imperial Airways Empire Class S23 flying boats were dismantled at Hythe in 1947.

Empire C Class S23 flying boat G-ADVB Corsair being broken up at Hythe in January 1947. Photo supplied by Mike Phipp, author of ‘Flying Boats of the Solent and Poole’ book pub. 2013.

BOAC terminated all of it’s flying boat operations in November 1950.

A number of BOAC Hythe class flying boats were scrapped at the Hythe base while a few survived and continued to see service when purchased by Hamble based Aquila Airways (with a number of other BOAC flying boats primarily for its Southampton to Madeira and Canary Island routes) albeit the Hythe’s were used in only a limited capacity until 1955. Aquila Airways ceased it’s flying boat operations in the summer of 1958.


BOAC became British Airways in 1974. British Airways recognises its Hythe flying boat heritage; British Airways February 1949 archive stating: 

“The last of the Hythe flying boat services took place. By the end of the service, BOAC Sunderland and Hythe flying boats flew 25,111,246 miles and carried 79,793 passengers.”

On 27 July 1998, a Catalina flying boat visiting Southampton Water crashed just off Hythe whilst undertaking a ‘touch and go’ (as practise for the Sea Wings 2000 Millennium Celebration scheduled to take place on Southampton Water in June 2000); sadly, two crew would lose their lives. The badly damaged Catalina was brought ashore at RAF Hythe (the old Hythe flying boat base) and subsequently taken to Hamble before being transported to Ireland. A Grumman Goose and an Albatross flying boat provided the flying boat displays for the Sea Wings 2000 event.

Whilst the days of flying boats at Hythe are now long gone, the names of some of the iconic flying boats that were based in Hythe can still be seen today. Roads that begin with the letter ‘C’ starting with Cabot Drive / Cygnus Gardens / Courtier Close (off Claypits Lane) all the way along Cumberland Way and through to Corinna Gardens / Cordelia Close (off Challenger Way) each share their name with an Imperial Airways Empire Class flying boat.

Credits & sources

  • Flying Boats of the Solent and Poole book – Mike Phipp pub. 2013
  • Imperial Airways Empire Flying Boat Services – Peter Wingent pub. 1997
  • Historic England (history of Hythe flying boat site inc. Heinkel 115s at Hythe during WW2)
  • The Southern Daily Echo (Imperial Airways and BOAC news reports)
  • The Waterside Heritage Centre, Hythe (Grove Building, Hythe records)
  • The Supermariners (Vickers Supermarine at Hythe)
  • Grace’s Guide (Imperial Airways)
  • Botwood Heritage Society (Transatlantic Flying Boat records)
  • British Airways Archives (Imperial Airways and BOAC records)
  • International Churchill Association (January 1942 ‘Berwick’ flight)
  • Stars & Stripes Publication (RAF Hythe)