. A simple solution describing flanking of a seawall was obtained by using two different solution areas where the longshore sand transport rate and breaking-wave angle vary. A similar technique was used to model diffraction downdrift of a groin or jetty by allowing the wave angle to vary with the distance alongshore according to a specified function of by employing a large number of solutions areas. Cases were also presented for the accumulation updrift a groin and the shoreline response in a groin compartment with a breaking-wave angle that varies sinusoidally in time. A solution for a single groin illustrated the impact of bypassing on the updrift accumulation. The solutions could be fit to measured shorelines, and the net characteristics of the effective wave climate and longshore transport rate estimated.