'Frankton' was a British special forces raid by the Special Boat Section ('Boom Patrol Detachment') to destroy German shipping in the port of Bordeaux in south-western France (7/12 December 1942).

The plan was for the six Cockle Mk II two-man canoes to be transported to the area of the Gironde estuary by submarine, and after launch for them to be paddled by night to Bordeaux, where the German garrison was headed by Admiral Johannes Bachmann, heading the Marinebefehlshaber Westfrankreich command. On arrival the six two-man parties were to attack the docked cargo ships with limpet mines and then escape overland to Spain. Twelve men from No.1 section were selected for the raid and, together with the commanding officer and one reserve, the party therefore totalled 13 men. Only two men survived the raid.

The Royal Marines Boom Patrol Detachment had been formed on 6 July 1942 at Southsea near Portsmouth, and was commanded by a Royal Marines officer, Major Herbert 'Blondie' Hasler with Captain J. D. Stewart as his second in command. The detachment comprised 34 men and, based at Lumps Fort, often exercised in Portsmouth harbour and patrolled the harbour boom at night.

Up the Gironde estuary from the east coast of the Bay of Biscay, the port of Bordeaux was a major destination for goods to support the German war effort. In the 12 months from June 1941, vegetable and animal oils, other raw materials, and 25,000 tons of raw rubber arrived at the port in ships including a number of blockade runners, so the port and the ships in it were targets of some strategic value. Hasler submitted a plan to attack this target on 21 September 1942, his initial submission calling for a force of three canoes to be transported by submarine to the Gironde estuary, up which the canoes would be paddled by night, hiding by day, until they reached Bordeaux some 60 miles (100 km) from the sea. Hasler believed that this approach would allow the attack party to avoid the 32 assorted German naval vessels (six minesweepers, 12 S-boote, 12 patrol craft and two armed trawlers) which patrolled or used the port under the local supervision of the Hafenkommandant Bordeaux command. On arrival the canoeists hoped to sink between six and 12 cargo ships then escape overland to Spain.

Authorisation for the raid was granted on 13 October 1942, but Admiral the Lord Louis Mountbatten, chief of Combined Operations, increased the number of canoes involved from three to six. Mountbatten originally ordered Hasler not take part in the raid, because he was the command’s most experienced canoeing specialist, but changed his mind after Hasler, the only man with experience in small boats, formally submitted his reasons for inclusion.

On 20 October the RMBPD started training for the raid, this including canoe handling, submarine rehearsals, the handling of limpet mines, and escape and evasion exercises. The RMBPD practised for the raid with a simulated attack against Deptford, starting from Margate and canoeing up the Swale river. separating the Isle of Sheppey from Kent.

The Canoe Mk II, codenamed the Cockle, was selected for the raid. This canoe was a semi-rigid two-man type 15 ft (4.6 m) long with a flat bottom and canvas sides and decking. The collapsed canoe had to be manoeuvrable through the 24 in (0.61 cm) diameter of the standard submarine hatch. For the raid, each canoe was to carry two men, eight limpet mines, three sets of paddles, a compass, a depth-sounding reel, repair bag, torch, camouflage net, waterproof watch, fishing line, two hand grenades, rations and water for six days, a spanner to activate the mines and a magnet to hold the canoe against the side of cargo ships. Each man also carried a 0.45-in (11.4-mm) pistol and a Fairbairn-Sykes Fighting Knife.

The men selected to go on the raid were divided into two divisions, each with its own targets. A Division comprised Hasler and Marine 'Bill' Sparks in canoe Catfish, Corporal A. F. Laver and Marine W. H. Mills in Crayfish and Corporal G. J. Sheard and Marine D. Moffatt in Conger, while B Division comprised Lieutenant J. W. Mackinnon and Marine J. Conway in Cuttlefish, Sergeant S. Wallace and Marine R. Ewart in Coalfish and Marine W. A. Ellery and Marine E. Fisher in Cachalot. A thirteenth man, Marine N. Colley, was taken as reserve.

On 30 November the British submarine Tuna departed Holy Loch in Scotland with the six canoes and 13 raiders on board. The submarine was supposed to reach the Gironde estuary and the mission was scheduled to start on 6 December 1942, but was delayed by bad weather en route and the need to undertake the slow negotiation of a minefield. By 7 December 1942 the submarine had reached the Gironde estuary and surfaced some 10 miles (16 km) from its mouth. Cachalot's hull was damaged while being passed through the submarine hatch, leaving just five canoes to start the raid. Colley, the reserve, remained on board the submarine with Cachalot's crew, Ellery and Fisher.

The five remaining canoes were disembarked at 17.30 on 7 December. The plan was for the crews to paddle with a five-minute rest every hour. During the first night, 7/8 December, as the canoes fought against strong cross tides and cross winds, Coalfish disappeared but later rejoined. As they proceeded up the estuary, the remaining crews encountered 5-ft (1.5-m) waves and Conger capsized and was lost. The canoe’s crew, Sheard and Moffatt, held on to two of the remaining canoes, which were paddled as close to the shore as possible before the two towed men let go and started to swim ashore.

Carrying on with the raid, the four remaining canoes approached a major checkpoint in the estuary, where there were three German warships. Lying flat on the canoes and paddling silently, the six men managed to get by without being discovered, but Cuttlefish[ (Mackinnon and Conway) became separated. On the first night the three remaining canoes, Catfish, Crayfish and Coalfish, managed to cover 20 miles (32 km) in five hours and landed near St Vivien du Médoc. While they were hiding during the day, and unknown to the others, Wallace and Ewart in Coalfish were captured beside the Pointe de Grave lighthouse where they had come ashore. By the end of the second night, 8/9 December, the two remaining canoes, Catfish and Crayfish, had covered another 22 miles (35 km) in six hours; on the third night, 9/10 December, they paddled 15 miles (24 km); and on the fourth night, 10/11 December, they travelled only 9 miles (14.5 km) because of the strong ebb tide. The original plan had called for the raid to be carried out on 10 December, but Hasler now had to change the plan. Because of the strength of the ebb tide, the men still had a short distance to cover, so Hasler ordered that they hide for another day and set off to reach Bordeaux on the night of 11/12 December. After a night’s rest the men spent the day preparing their equipment and limpet mines. Hasler decided that Catfish would cover the western side of the docks and Crayfish the eastern side.

The two remaining canoes reached Bordeaux on the fifth night, 11/12 December. The river was flat calm and the sky clear, and the attack began at 21.00 hours. Hasler and Sparks in Catfish attacked the shipping on the western side of the dock, placing eight limpet mines on four vessels including a Sperrbrecher auxiliary minesweeper and patrol boat. A sentry on the deck of the Sperrbrecher, apparently spotting something, shone his torch down toward the water, but the camouflaged canoe evaded detection in the darkness. The men had planted all their mines and left the harbour on the ebb tide at 00.45. At the same time Laver and Mills in Crayfish had reached the eastern side of the dock without finding any targets, so returned to deal with the ships docked at Bassens. They placed eight limpet mines on two vessels, five on a large cargo ship and three on a small liner.

On their way down the river the two canoes met by chance on the Ile de Caseau. They continued down river in company until 06.00, when they beached their canoes near St Genes de Blaye and tried to conceal them by sinking them. The two crews then set out separately, on foot, for the Spanish border. After two days Laver and Mills were captured at Montlieu la Garde by the Vichy French gendarmerie and handed over to the Germans. Hasler and Sparks arrived in the French town of Ruffec, 100 miles (160 km) from the point at which they had beached their canoe, on 18 December, and here made contact with a member of the French resistance at the Hotel de la Toque Blanche, from which they were taken to a local farm. They spent the next 18 days here in hiding before being guided across the Pyrenees mountains into neutral Spain.

On 10 December the Germans announced that a sabotage squad had been caught on 8 December near the mouth of the Gironde and supposedly killed in action. In the absence of other information, during January 1943 the 10 men on the raid were posted as missing, and it was only on 23 February that it was learned that Hasler and Sparks were safe. On 2 April Hasler arrived back in the UK by air from Gibraltar, and Sparks returned at a later date by sea.

Though not all of the limpet mines attached to target ships detonated, it was believed that four cargo ships (6,725-ton Alabama, 7,840-ton Tannenfels, 7,132-ton Portland and 5,567-ton Dresden) were flooded, and that a Sperrbrecher had also beem damaged.

Later it was confirmed that five ships had been damaged in Bordeaux by mysterious explosions, although research in 2010 revealed that a sixth ship had also been damaged, this even more extensively than any of the other five reported. This research also revealed that the other five ships had been returned to service quite quickly.

Of the raid’s other members, Wallace and Ewart were captured on 8 December at the Pointe de Grave, near Le Verdon, and were executed under the terms of Adolf Hitler’s 'commando order' on the night of 11/12 December in a sandpit in a wood to the north of Bordeaux and not at the Château Magnol near Blanquefort as earlier believed.

After being set ashore, Mackinnon and Conway managed to evade capture for four days, but were betrayed and arrested by the gendarmerie and handed over to the Germans at La Réole hospital some 30 miles (48 km) to the south-east of Bordeaux as they attempted to make their way to the Spanish border. Mackinnon had been admitted to the hospital for treatment for an infected knee. The exact date of their execution is not known, but new evidence indicates that Mackinnon, Laver, Mills and Conway were not executed in Paris but in the same location as Wallace and Ewart.

Sheard and Moffatt were not drowned on the first night, but died of the cold. Moffatt’s body was found on the Ile de Ré on 14 December, and it is believed that Sheard’s body was recovered and buried elsewhere farther to the north on the French coast.