Abstract: Effects of submerged structure on a wave-current field are studied numerically by means of BEM. The potential flow field is assumed to be composed of a steady current potential and an unsteady wave potential, where the Dopler effect is taken into consideration. The current velocities affected by the submerged structures were determined by using the three-dimensional boundary element method. Dispersion relations affected by the presence of current are used to calculate the apparent wave frequencies. Wave height distributions in the wave-current field were estimated.