After being acquired by SOE the ‘Mutin’ (Mutineer) was based in the Helford Estuary in Cornwall. Its paintwork was aged and was disguised as a French tuner fishing vessel and the all British crew dressed as Breton fishermen. Part of her refit was a more powerful diesel engine and a wireless using RAF frequencies to support the illusion that transmissions were not from an ocean vessel and its long aerial was built into the rigging. There is an account from a Quartermaster in the Royal Navy who volunteered for clandestine operations without being told what these operations were. This new volunteer later said, on his arrival at the quay he saw Mutin which had just returned from Brittany after dropping off agents: “I saw heaps of sail on the deck covered in blood. Shipwrights were digging shrapnel from bow to stern and I thought, God what have I let myself in for”?… “I was later told, after dropping off agents Mutin was spotted by a German aircraft and raked by cannon fire during which the engineer was killed.
More details in my forthcoming book SOE in France