As part of the investigations for a major expansion of the Port of Hanstholm a series of hydraulic studies were carried out involving: field measurements of waves and currents, establishment of design conditions for waves and currents, analysis of the wave disturbance, laboratory tests of breakwater stability, analysis of the future conditions for sediment bypass and sedimentation and possible impact on the surrounding coastlines. In this paper the extensive sediment studies made by application of numerical modelling is described.