Yes, seems a reasonable answer. As you probably know the area off the Biscay coastal ports had been divided in to areas around the entrances to each port, Lorient = Artichokes, Brest =Jellyfish V, St Nazaire = Beech and La Pallice = Cinnamon. The RAF continually kept replenishing each one by dropping mines throughout the later war years. Of other possible causes of her loss, she being relatively a new boat only entering service at the end of May 1943 and having just spent two months in port, but having been attacked twice by aircraft on her previous patrol I would have thought any major structural problems would have been picked up so that as a possible cause seems unlikely. Crew error in some way during diving tests cannot be ruled out of course. John