Five deployments of a boundary layer probe were undertaken on the Long Island inner continental shelf between 1976 and 1978. The probe measured suspended sediment concentration and fluid velocity 100 cm above the bottom. Multivariate analysis of the data from all deployments shows that surface wave activity is the major determinant of suspended sediment concentration. Concentration is found to be proportional to the wave orbital velocity when the velocity is above a threshold value. Both the threshold value (WST) and the proportionality constant (&bgr;) seem to depend on the composition of the local sediment substrate; WST increasing with the mean size of the coarse fraction, &bgr; increasing with the amount of finegrained (<62&mgr;) material.