A three-year study of Price Inlet, South Carolina, monitored inlet hydraulics and channel morphology. The velocity asymmetry is caused by changes in inlet efficiency during the tidal cycle. The intertidal marsh experiences a change in open water surface area of 670 percent during an average tidal cycle. At high tide, the large water surface causes inefficient exchange of water through the inlet and a long time lag between ocean and bay tides. The small surface area of open water at low tide yields nearly no time lag. These time lags cause longer flood durations than ebb durations in the inlet throat and, consequently, stronger ebb velocities. The cross-sectional flow area of the inlet throat demonstrated rapid adjustment to changing flow conditions. The 1159 m 2 cross sectional area of the inlet throat varied as much as 8.3 percent during one tidal cycle. Long-term changes in the dimensions of the channel appear to be a result of changes in the size of ebb-tidal delta shoals.--Modified journal abstract.