Presents experimental data on the characteristics of the reflected wave which forms when a solitary wave meets a vertical porous structure. The wave flume laboratory experiments and results are discussed. Deformation of the reflected wave observed in these experiments was further investigated in computer simulation studies and is described in detail. The major findings of the study were: the reflected wave initially has the same value of the pulse width (phase) parameter as the incoming solitary wave, its profile deforms during its propagation to a single solitary wave of reduced height with a depression tail, and its volume increases during deformation due to transfer of water from the developing depression tail. (J.M.M.)