The crew quickly became familiar with the sounds of their stalkers: first, a click as the exploder in the depth charge functioned, then the sound of the explosion, then the hissing surge of water along the hull. Like thunder following lightning, the time between the initial click and the explosion signals the distance of the depth charge from the boat. Soon, click and wham came closer together, slamming concussive waves of water against the hull. The S-39 bucked and plunged, flinging men around like rag-dolls. The steel hull flexed in and out, vibrating all the gear. The air filled up with dust, paint-chips, and bits of cork that had lined the inner walls; men ducked their heads against bolts and screws flying through the air like shrapnel. Lightbulbs smashed, leaving them blind. The temperature in the battened- down boat crept up over 110 degrees. Men tensed their stomach-muscles against the powerful instinct of fight or flight, forcing themselves to huddle in soundless despair against the next charge.
