French submarine Surcouf

Soon after Surcouf was launched, the London Naval Treaty finally placed restrictions on submarine designs. Among other things, each signatory (France included) was permitted to possess no more than three large submarines, each not exceeding 2,800 long tons (2,800 t) standard displacement, with guns not exceeding 6.1 in (150 mm) in caliber. Surcouf, which would have exceeded these limits, was specially exempt from the rules at the insistence of Navy Minister Georges Leygues,[4] but other 'big-gun' submarines of this boat's class could no longer be built.

Seizure of Surcouf
Part of World War II
Date 3 July 1940 Location Plymouth, England, United Kingdom Result British capture of Surcouf
Belligerents
United Kingdom	France
Casualties and losses
3 killed	1 killed

In 1940, Surcouf was based in Cherbourg, but in May, when the Germans invaded, she was being refitted in Brest following a mission in the Antilles and Gulf of Guinea. Under command of Frigate Captain Martin, unable to dive and with only one engine functioning and a jammed rudder, she limped across the English Channel and sought refuge in Plymouth.

On 3 July, the British, concerned that the French Fleet would be taken over by the German Kriegsmarine at the French armistice, executed Operation Catapult. The Royal Navy blockaded the harbours where French warships were anchored, and delivered an ultimatum: rejoin the fight against Germany, be put out of reach of the Germans, or scuttle. Few accepted willingly; the North African fleet at Mers-el-Kebir and the ships based at Dakar (French West Africa) refused. The French battleships in North Africa were eventually attacked and all but one sunk at their moorings by the Mediterranean Fleet.

French ships lying at ports in Britain and Canada were also boarded by armed marines, sailors and soldiers, but the only serious incident took place at Plymouth aboard Surcouf on 3 July, when two Royal Navy submarine officers, Commander Denis 'Lofty' Sprague, captain of HMS Thames, and Lieutenant Patrick Griffiths of HMS Rorqual,[6][7] and French warrant officer mechanic Yves Daniel[8] were fatally wounded, and a British seaman, Albert Webb,[6] was shot dead by the submarine's doctor.[9]

By August 1940, the British completed Surcouf's refit and turned her over to the Free French Naval Forces (Forces Navales Françaises Libres, FNFL) for convoy patrol. The only officer not repatriated from the original crew, Frigate Captain Georges Louis Blaison, became the new commanding officer. Because of Anglo-French tensions with regard to the submarine, accusations were made by each side that the other was spying for Vichy France; the British also claimed Surcouf was attacking British ships. Later, a British officer and two sailors were put aboard for "liaison" purposes. One real drawback was she required a crew of 110–130 men, which represented three crews of more conventional submarines. This led to Royal Navy reluctance to recommission her.

Surcouf then went to the Canadian base at Halifax, Nova Scotia and escorted trans-Atlantic convoys. In April 1941, she was damaged by a German plane at Devonport.[8]

On 28 July, Surcouf went to the United States Naval Shipyard at Kittery, Maine for a three-month refit.[4]

After leaving the shipyard, Surcouf went to New London, Connecticut, perhaps to receive additional training for her crew. Surcouf left New London on 27 November to return to Halifax.

In December 1941, Surcouf carried the Free French Admiral Émile Muselier to Canada, putting into Quebec City. While the Admiral was in Ottawa, conferring with the Canadian government, Surcouf's captain was approached by The New York Times reporter Ira Wolfert and questioned about the rumours the submarine would liberate Saint-Pierre and Miquelon for Free France. Wolfert accompanied the submarine to Halifax, where, on 20 December, they joined Free French "Escorteurs" corvettes Mimosa, Aconit, and Alysse, and on 24 December, took control of the islands for Free France without resistance.

United States Secretary of State Cordell Hull had just concluded an agreement with the Vichy government guaranteeing the neutrality of French possessions in the Western hemisphere, and he threatened to resign unless President of the United States Franklin D. Roosevelt demanded a restoration of the status quo. Roosevelt did so, but when Charles de Gaulle refused, Roosevelt dropped the matter. Ira Wolfert's stories – very favourable to the Free French (and bearing no sign of kidnapping or other duress) – helped swing American popular opinion away from Vichy. The Axis Powers' declaration of war on the United States in December 1941 negated the agreement, but the U.S. did not sever diplomatic ties with the Vichy Government until November 1942.

In January 1942, the Free French leadership decided to send Surcouf to the Pacific theatre, after she had been re-supplied at the Royal Naval Dockyard in Bermuda. However, her movement south triggered rumours that Surcouf was going to liberate Martinique from the Vichy regime.

In fact, Surcouf was bound for Sydney, Australia, via Tahiti.[4] She departed Halifax on 2 February for Bermuda, which she left on 12 February, bound for the Panama Canal.[8]

The Free French Memorial on Lyle Hill, Greenock: À la mémoire du Capitaine de frégate Blaison, des officiers et de l'équipage du sous-marin Surcouf perdu dans l'Atlantique Février 1942 ("To the memory of Frigate Captain Blaison, the officers[,] and the crew of the submarine Surcouf[,] lost in the Atlantic February 1942").

Surcouf vanished on the night of 18/19 February 1942, about 130 km (70 nmi) north of Cristóbal, Panama, while en route for Tahiti, via the Panama Canal. An American report concluded the disappearance was due to an accidental collision with the American freighter Thompson Lykes. Steaming alone from Guantanamo Bay on what was a very dark night, the freighter reported hitting and running down a partially submerged object which scraped along her side and keel. Her lookouts heard people in the water but, thinking she had hit a U-boat, the freighter did not stop although cries for help were heard in English. A signal was sent to Panama describing the incident.[10][11]

The loss resulted in 130 deaths (including 4 Royal Navy personnel), under the command of Frigate Captain Georges Louis Nicolas Blaison. The loss of Surcouf was announced by the Free French Headquarters in London on 18 April 1942, and was reported in The New York Times the next day.[12] It was not reported Surcouf was sunk as the result of a collision with the Thompson Lykes until January 1945.[13]

The investigation of the French commission concluded the disappearance was the consequence of misunderstanding. A Consolidated PBY, patrolling the same waters on the night of 18/19 February, could have attacked Surcouf believing her to be German or Japanese. This theory could have been backed by several elements:

• The witness testimonies of cargo ship SS Thompson Lykes, which accidentally collided with a submarine, described a submarine smaller than Surcouf
• The damage to the Thompson Lykes was too light for a collision with Surcouf
• The position of Surcouf did not correspond to any position of German submarines at that moment
• The Germans did not register any submarine loss in that sector during the war.

Inquiries into the incident were haphazard and late, while a later French inquiry supported the idea that the sinking had been due to "friendly fire"; this conclusion was supported by Rear Admiral Auphan in his book The French Navy in World War II.[14] Charles de Gaulle stated in his memoirs[15] that Surcouf "had sunk with all hands".

Possible site of the Surcouf's sinking, if it collided with the Thompson Lykes.

As no one has officially dived or verified the wreck of Surcouf, its location is unknown. If one assumes the Thompson Lykes incident was indeed the event of Surcouf's sinking, then the wreck would lie 3,000 m (9,800 ft) deep at 10°40′N 79°32′W.[4]

A monument commemorates the loss in the port of Cherbourg in Normandy, France.[16] The loss is also commemorated by the Free French Memorial on Lyle Hill in Greenock, Scotland.[17]

Model of Surcouf in Paris

As there is no conclusive confirmation that Thompson Lykes collided with Surcouf, and her wreck has yet to be discovered, there are alternative stories of her fate. James Rusbridger examined some of these theories in his book Who Sank Surcouf?, finding them all easily dismissed except one: the records of the 6th Heavy Bomber Group operating out of Panama show them sinking a large submarine the morning of 19 February. Since no German submarine was lost in the area on that date, it could have been Surcouf. He suggested the collision had damaged Surcouf's radio and the stricken boat limped towards Panama hoping for the best.[18]

A conspiracy theory, based on no significant evidence, held that the Surcouf, during its stationing at New London in late 1941, had been caught treacherously supplying a German U-boat in Long Island Sound, pursued by the American training subs Marlin and Mackerel out of New London, and sunk. The rumor circulated into the early 21st century, but is false since the Surcouf's later movements south are well documented.[19]