In this paper are given the results of an experimental study of the interaction of an explosion wave with a water‐backed steel plate. Data are given showing the dependence of the transmitted and reflected waves on the angle of incidence, and of the diffracted wave on position behind the plate. These data are illustrative of the use of the explosion wave in acoustical research. The plate acts as a filter, removing the high frequencies from the transmitted wave and the low frequencies from the reflected wave. The reflected wave is approximately constant in shape, or time scale, with varying angle of incidence. Its amplitude has a broad maximum at normal incidence. In addition to the reflected, transmitted, and diffracted waves, waves can travel along the plate, in which case the plate acts as a wave guide. As a consequence of dispersion in the guided waves, a precursor precedes the explosion wave as it travels along the plate. The dependence of the frequency, length, and amplitude of this precursor upon orientation of the plate, position, and time has been determined.