202 



TRANSMISSION OF EXPLOSIVE SOUND IN THE SEA 



SHOT 7 RANGE 960 YARDS 



SHOT 17 RANGE 1950 YARDS 



SHOT 23 



RANGE 2520 YARDS 



Figure 7. Changes in the shape of an explosive pulse on passing from the direct zone into the shadow zone. Source: 

 No. 8 cap at depth 100 feet and at ranges indicated. Hydrophone at depth 54 feet. Date: Apr. 3, 1942; gain of recording 

 system sometimes changed between shots. 



