The River Waal is the largest river in The Netherlands, and its shipping density is among the highest of all the inland waterways of the world. The river bed sediments of the Waal are mainly sandy. To protect the river banks from erosion, groynes have been built all along the river. The groynes are submerged at high discharges only, and it is hypothesized that the sandy beaches between the groynes are the result of a balance between sand deposition at high discharges and sand erosion by currents induced by navigation traffic at moderate and low discharges. In the summer of 1996, currents and sediment resuspension resulting from navigation traffic were measured between the groynes. The largest vessels had the strongest impact, typically creating a water-level depression of 15-20 cm and currents of 30-40 cm s^-1 at 10 cm above the bed. Scaling sand transport from groyne fields up to the entire river and a time-scale of 1 yr results in overestimates of sand losses from the groyne fields, suggesting that more measurements in groyne fields with different orientations and at different discharge conditions have to be carried out. Models in the literature that relate vessel characteristics to currents induced near the bank do not seem to serve for the conditions of the navigation traffic in the River Waal.