In this contribution we report on modeling underwater explosion in the framework of molecular dynamics. Calculations displayed the striking resemblance of the underwater explosions modeled and those of observed in real processes; namely, generation of a shock wave and its expanding; formation of a cavity; disintegrating the shock wave, when reaching a surface, transforming the cavity into a water crater of an arising water volcano. For studying the structure of shock waves, a special technique was developed. It allowed observing the form of a shock wave and estimating its velocity. It was found that the shape of a shock wave is changing with time as if the shock wave disintegrated into two parts.