Process of dilution and hydrate forming beyond the front of the shock wave with moderate amplitude (moderate shock wave front) in water with carbonic gas bubbles at varying initial static pressures has been experimentally observed and studied. Influence of surfactants on dilution and hydrate forming process beyond the shock wave occurring in the medium has been scrutinized. It has been proved that beyond the moderate shock wave in fluid with carbonic gas bubbles intense process of dilution and hydrate forming occurs resulting in complete loss of gas phase for several milliseconds. Surfactants present in the medium proved to be insignificant for dilution and hydrate forming process in the studied time range. Dependence of dilution and hydrate forming process beyond the shock wave from wave and medium parameters has been revealed. Theoretical model of dilution and hydrate forming process beyond the shock wave in gas and fluid medium taking into account convective and molecular gas diffusion in fluid, convective and conductive heat exchange caused by heat release in interphase boundary resulted from dilution and hydrate forming has been offered. Close fit of experimental data and calculations has been achieved. (C) 2009 Published by Elsevier Ltd.