41. In the words of Alan Hotham, British Director of Naval Intelligence, ASDIC was a " huge bluff ". 42. The effectiveness of early ASDIC was hamstrung by the use of the depth charge as an anti-submarine weapon. 43. The confidential papers were consigned to the sea bed, and the Asdics were destroyed and the pieces thrown overboard. 44. Best of luck " and " Safety of personnel would be your first consideration after destruction of the Asdics ". 45. Throughout 1935 and 1936, D�nitz had misgivings regarding submarines due to German overestimation of the capabilities of British ASDIC intelligence. 46. Developments during the war resulted in British ASDIC sets which used several different shapes of beam, continuously covering blind spots. 47. The U-boat anechoic tile rubber coating, one layer of which contained circular air pockets to defeat ASDIC sonar. 48. The first passive sonar hydrophones were introduced into the RN in 1914 while ASDIC ( active sonar ) came in afterwards. 49. At 0406 " Vidette " made an ASDIC contact at, and made a hedgehog attack causing two explosions. 50. This time he was involved in ASDIC ( Anti-Submarine Detection Investigation Committee ) which is known today as sonar.
