Wednesday, June 14, 2017

The 'Mystery Boats' of Tresco Island

By Mike Williams

Five inhabited islands of outstanding beauty, together with over one hundred islets and large rocks rising out of the Atlantic make up the Isles of Scilly. Lying some 28 miles west of Lands End, they provide an ideal anchorage for flotillas of small boats engaged in covert operations. During the English Civil War Royalist privateers operating out of Scilly became the scourge of both Parliamentarian and foreign merchant ships - especially the Dutch. It eventually took an uneasy alliance between Cromwell’s General-at-Sea Monk and the Dutch admiral van Tromp to bring the piratical Royalists to heel.

Almost 300 years later, Churchill’s rallying cry to “Set Europe ablaze!” did much to galvanise both SOE (the Special Operations Executive) and the SIS (the Secret Intelligence Service) into action, following the fall of France in 1940. One immediate result was the emergence of many so-called small “Special Forces” units. While SOE quickly began to regard itself as a striking force, attacking the enemy wherever it could, SIS was intended to be responsible for the infiltration and exfiltration of Allied agents and vital intelligence, between Great Britain and Nazi-occupied Europe.

Working under Commander Slocum RN, who had been tasked with re-establishing direct communications with Resistance groups in Nazi-occupied Europe, RNVR Officers- Stephen Mackenzie, Daniel Lomenech - a Breton - and others began exploring the use of converted fishing boats to convey both agents and intelligence to and from Brittany.

The idea quickly turned into workable reality as two such “spy-boats” were quickly developed with the professional help of British marine architects and small boat manufacturers. The traditional style of fishing boat was chosen because they were accepted by the Germans who allowed them to remain at sea for up to three nights at a time. This relaxation of rules played right into the hands of British intelligence.

A major issue was the need for far greater speed than the usual plodding pace of a genuine fishing boat. In order to enter the coastal waters of occupied France and mingle with the large fleets of Breton fishing boats, without raising suspicion, the British boats would need to race from Scilly across approximately 100 miles of sea, under cover of darkness, to arrive off the Breton coast by early dawn. Coded radio messages and mast-head pennants of pre-arranged colours would identify which of the local Breton boats would be the contact vessel for the inshore transfer of agents, crucial intelligence, or weapons and explosives, off the Breton coast.

Lomenech who was familiar with the Breton fishing industry personally oversaw much of the conversion work to ensure as much authenticity as possible in the transformations He knew that the real test was not to convince the Germans, but to avoid raising questions in the minds of the patrol boat crews of the French Harbour Gendarmerie.

In consultation with Lomenech and other RNVR Officers, British boat designers cleverly re-configured the boats’ underwater hulls and fitted new far more powerful engines, giving the boats a top speed in excess of 30 knots. Because of its remoteness, privacy from prying eyes and sheltered waters, Tresco Island’s New Grimsby Sound was chosen as the base for the new secret flotilla. The former World War One flying boat base also conveniently situated at Tresco provided storage facilities, workshops and also some accommodation. . . .

One of the secret flotilla’s first tasks was to deliver two key French agents to the Resistance movement, close to Concarneau, during April 1941.The French Resistance had talked about using a submarine for the job, but were over-ruled by the British Admiralty who viewed such craft as pure gold. Instead it was agreed to deliver the agent by Angele Rouge one of the two “doctored” fishing boats newly arrived in Tresco’s New Grimsby harbour anchorage, under the shelter of Braiden Rock.

The boats were delivered to Tresco painted British “Pusser’s grey” so that they blended in with other RN boats at anchor, giving the impression to curious observers that they were some sort of minor naval auxiliary vessel. It was at the eleventh hour, before a cross-Channel operation into enemy waters that, under Daniel Lomenech’s expert direction, the boats were painted in the garish colours typical of Breton fishing vessels. One trick devised by the crews painting the boats was to mix iron filings in with the paint. On contact with the sea the fresh paint quickly took on a convincing weathered appearance. Locals quickly dubbed them “The mystery boats”.

Aerial View of the Scilly Isles (Public Domain Image)

Lobsters, crabs and other fish freshly caught in Scillonian waters were packed in barrels, in ice, to add a touch of authenticity and crew members filled the strategically placed “operations boxes” with their personal weapons also covered with fish. These ensured that should they be stopped and fail to convince the Authorities that they were Breton fishermen, they could call upon significant firepower in a fire-fight. Adding to the illusion of Breton fishermen, RNVR personnel wore similar working rig to their French counterparts. All boats carried at least one Breton who could speak his native tongue, as well as French.

A model of a Breton fishing boat, built & photographed by the author

At midnight Angele Rouge, slipped her moorings at Braiden Rock, the secret flotilla’s anchorage below Cromwell’s Castle, on Tresco’s western shore, heading south. The incoming tide saw her cautiously navigate the shallow waters of Tresco Flats, before she opened up her two 500 hp Hall Scott engines and began punching her way, at over 20 knots, through the rolling whitecaps of St Mary’s Road. Once through St Mary’s Sound and with St Agnes astern to starboard, her youthful skipper ordered his coxswain to maintain maximum revolutions, to arrive off the Breton coast in time to mingle with the French fishing fleets around dawn.

Below decks, each with their private thoughts and fears, the two agents sat huddled in silence, sipping steaming mugs of “kye”, the Royal Navy’s own glutinous chocolate nectar. Both were SOE French Section recruits. One was a former French army lieutenant, code-named “Antoine”, who had escaped from France in the evacuation from Dunkirk. The other, “Marie-Claude”, a young woman of Anglo-French parents, had been selected for espionage operations by SOE’s formidable Vera Atkins.

Vera Atkins (Public Domain Image)

SOE’s creative technologists - the real-live versions of James Bond’s “Q” - developed the weaponry and kit essential in covert operations - some of them so bizarre as to beggar belief. One such example was that of ingeniously crafted dummy lobsters, to be used for carrying secret intelligence.

Unfortunately the design team had only ever seen cooked lobsters, which turn pink as a result of boiling. It was a fisherman who told them in no uncertain terms that lobsters, as caught in the sea, are dark blue! Many an SOE face turned bright red when the error was spotted. On this trip, Angele Rouge carried no fanciful confections from the “Gadgets” Section - only radios packed in tobacco and sealed in French petrol drums, for the Resistance.

With the first signs of dawn beginning to lighten the sky, Angel Rouge was some 12 miles north of Ushant. To preserve the anonymity essential to her cover, her skipper ordered “Reduce speed to six knots, we’ll shortly be joining the locals.” Poring over their charts, with Ushant astern, the skipper and coxswain navigated Angele Rouge through the scattered islands and rock outcrops west of the Brittany coast, maintaining a course due south.

The entrance to the sheltered waters of Brest on her port bow, Angele Rouge flying her yellow mutual recognition pennant, slowly turned heading for Camaret, the RV with the local crabber, Monique, which would take the agents ashore. Almost right on the ETA of 07.30 hours, the crabber appeared, flying a similar yellow pennant. Three miles offshore, under the guns of the German coastal batteries, the two boats drew alongside feigning a noisy chance meeting, of old fishing colleagues. Under the pretence of energetically hauling in nets, the crew slipped the agents from one vessel to the other. The confidential intelligence and radios in the fuel drums were also transferred and after more boisterous exchanges the two boats appeared to resume their fishing. Later, under cover of darkness, mission accomplished, Angele Rouge returned to her anchorage at Braiden Rock - and a fresh coat of Admiralty grey paint, minus iron-filings, securing around 23.00.

Map showing Brest and Camaret (See Commons attribution here)

Shortly after the transfer of the two agents, the Tresco flotilla was called upon to bring to England a leading Resistance Leader - Colonel Gilbert Rénault a.k.a. Colonel “Remy” - who had been betrayed and was in immediate danger of capture, inevitable torture and execution, by the Gestapo. The operation to rescue Colonel “Remy” and his family took the fishing boat Le Dinan to the remote Îles de Glénan, lying some twenty miles west of L’Orient.

65 feet in length, Le Dinan was longer than Angele Rouge and offered slightly more civilised accommodation for the Colonel, his wife and their children - including a 6-month-old baby. Because the waters around Brittany are among the most dangerous in the world - especially at night - the date of the pick-up was influenced by the weather, as well as the risks to Remy. Up-to-date weather forecasts were relayed to the crew on Tresco via a “scrambler” telephone, hidden in the heather at New Grimsby - as were top secret calls from SOE in London, and Government Communications at Bletchley Park. Inevitably it was the Gestapo’s imminent arrest of Remy which ultimately decided the date and RV of the rescue at sea.

Until three hours before nightfall, Le Dinan was given air cover by Beaufighters which, with a farewell waggle of wings, peeled off just north of Ushant, to return to Cornwall. This time, there would be no masthead recognition pennant, to look out for, but simply a white sail above a green hull. By 10 am the following morning, with the sea unusually calm, Le Dinan was plodding slowly through the Concarneau crabbing fleets. Skirting the towering Penmarc’h lighthouse she set course east and headed for the Îles de Glénan, her RV with the small fishing vessel bringing Remy and with him, vital up-to-date intelligence about the latest German coastal defences along the Normandy coast. Some 30 minutes ahead of schedule, Le Dinan’s crew sailed in among the islands to wait.

Map showing Ushant (See here for Commons attribution)

After an hour-and-a-half, lurking between the scattered islands, while awaiting the now well overdue lone white sail of the Colonel’s small boat to appear, the crew of Le Dinan were horrified to see a flotilla of five German corvettes belching black smoke and heading straight for them. Had the Colonel been picked up by the Kriegsmarine? Had the mission been compromised? Under the guise of hauling in their nets, the British held their nerve as the Germans steamed past them, at less than a cable’s distance, binoculars trained on them.

Shortly after the corvettes passed them in line astern, the awaited green hull and white sail appeared from behind one of the islands. Minutes later the Colonel - complete with German top secret intelligence of “Festung Europa”, his wife and children - including the tiny baby was safely onboard Le Dinan. After transferring supplies of tobacco, food and much needed oil and petrol, to the fishermen who brought Colonel “Remy”, she set course for Tresco.

Some 36 hours later and with their passengers now enjoying the fresh air, on deck, after the cramped conditions below, Le Dinan sailed into New Grimsby Sound and hove-to off Braiden Rock. Colonel Remy and his family were safe and British Intelligence had top secret German plans of the Normandy beach defences, so vital for planning the forthcoming D-Day invasion. Many more such hazardous operations were to take place before peace in Europe arrived in May 1945.

At a moving ceremony in July 2000 a commemorative plaque, honouring these gallant men was unveiled at Braiden Rock anchorage. Today, over 70 years later, the “mystery boats” and their crews are still remembered by Tresco’s older inhabitants.


Mike Williams MSc. is the published author of a trilogy of novels, based on a clandestine naval unit which operated out of the Isles of Scilly, during World War 2. Its role was to take secret agents and intelligence to and from Brittany, under the noses of the Nazis.
Published by Thorogood Publishing, London, titles are -
The Secret Channel
The Channel of Invasion
The Channel to Freedom
In September 2011 he presented his trilogy at the Marlborough LitFest. Available on Amazon.                                                  
His Cold War sequel -The Judas Trap -   is a story of counter-intelligence in response to a the insertion of Soviet spies in the Uk .
Available from the author:
Currently he is undertaking research for a novel about espionage in the English Civil War (In Treachery’s Shadow) set in the western counties,
Mike is a member of the Historical Writers’ Association.


  1. Fantastic story! I'm forever amazed at the innovation they devised to outwit the Germans.

  2. Thanks for posting this, Mike. Having just returned from Tresco (and it's wonderful gardens) I found this post extremely interesting. It gave the island/s a whole new dimension.

  3. Wonderful story, and a lovely place. People with courage like this are worthy of our remembrance and thanks.


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