Propagation of explosive signals in intermediate ocean depths

Experiments were conducted to measure the acoustic propagation loss and received signal characteristics for underwater transmission over distances of 10 to 100 nautical miles in ocean areas of intermediate water depth. Small explosive charges detonated at depths of 800 and 1500 ft were used as the signal source. With water depths of 1000 to 6000 ft, long range propagation was generally by bottom bounce. Wide differences were observed in the propagation loss at various test sites. Changes in propagation over a period of time was determined by crosscorrelation of a series of signals from sequential detonations.