ANNEX II C.O.S.(44) 185 (0) 21ST FEBRUARY, 1944 DEMOLITION OF U-BOAT BASES AND OTHER INSTALLATIONS IN LIBERATED TERRITORIES Memorandum by the First Sea Lord There are now in existence eight main U-boat bases with concrete shelters(a) France Marseilles, Bordeaux, St. Nazaire, Lorient, La Pallice, Brest. (b) Norway Trondhjem, Bergen. Authority to bomb the French bases was given in 1942, by which time the concrete shelters were already largely completed. In the event, it proved impossible to reduce the U-boat shelters by military action The shelters have been created entirely by the enemy to enable U-boats to prey upon world shipping.