Bed load transport rates on the shoreface and shelf are determined by tidal currents, wave-current interaction and grain
size. There is, however, a strong lack of field data and validated models because bed load transport under waves cannot
be measured in the field, while bed load transport by currents without waves commonly is barely measurable in spring
tidal conditions. Herein, bed load transports were carefully measured with a calibrated sampler in spring tidal conditions
without waves at a water depth of 13-18 m in fine and medium sands at 2 to 8.5 km offshore the Dutch coast. Near-bed
flow velocity was recorded at 2 Hz. The measurements are used to derive an empirical bed load model, in which
transports are normalized by grain size and density. The model produces bed load transports that are at least a factor 5
smaller than predicted by existing models. However, they agree with a large laboratory data set of sand and gravel
transport in currents near incipient motion. Cohesion of sediment due to mud in-mixing or biological activity was
excluded. Including turbulence probabilistically in bed load models strongly improves predictions near incipient
motion, and predict 20% more alongshore transport annually for currents only. The effect of wave-current interaction is
predicted to be twice as large, and the combined effect results in 100% larger transports. The effect of wave stirring is
gives much larger flood and ebb transports but the net transport is the same as for the combined wave-current
interaction and turbulence case. An overestimation of the current velocity leads to much larger transports than any of
the model combinations. Concluding, the effects of turbulence, wave-current interaction and wave stirring are of
secondary importance compared to the choice of empirical or existing bedload predictor and the representation of the
current climat