The collapse of the German front in Normandy left only the bases in German-occupied Norway nearest to the Atlantic. The newer boats were not forthcoming either. 90 XXI and 31 XIII's were built by the end of 1944. 60 of the former and 23 of the latter were in service but none were operational. Dönitz was left with the old VIIs to carry the war into 1945. A large number had snorkels, which enabled them to surface only upon reaching port. Submerged, this meant no radio or Enigma communications and far fewer sightings for the Allied intelligence network to exploit. Dönitz ordered his submarines to British coastal waters with some success in November and December 1944, achieving 85,639 tons. Admiral Andrew Cunningham remarked of the strategy, "We are having a difficult time with the U-boats...the air are about 90 percent out of business and Asdic is failing us." The inshore waters impeded the use of Asdic, which became confused with wrecks, rocks, and tidal swirls. The new types could conceivably have capitalised on these developments but the war was nearly over. On 1 January 1945, Dönitz had 425 submarines; 144 operational. On 1 April 1945, it was 166 from 429. He threw into battle every available weapon as the German Reich collapsed. Dönitz supported the use of Human torpedoes; the Neger, Marder, Seehund and Biber were all used in suicide missions on his orders, perhaps inspired by the Japanese Kamikaze.