The Germans began another development when the relatively small mine damage in the initial amphibious assaults at Anzio and Salerno indicated that the Allies had perfec-ted a method of detecting moored mines by ASDIC. The U-Boat Command for some time has been seeking an answer to the problem through special paints and coats of rubber. The Mine Command tested and rejected these. Very late in the war it hoped to eliminate rather than merely reduce the response obtained from cases with a metal core through design of an all sponge-rubber case with a minimum of rubber fittings.