The importance of velocity pulses on the flood and ebb tides in salt-marsh creeks has been noted in several studies, but no satisfactory explanation of the causal mechanisms has been made. This paper presents a critical analysis of existing models in the light of new field data from the Warham marshes, Norfolk, England. Measurements indicate that the assumptions of the continuity model approach, relating to the constant asymmetry of stage-time curves and the horizontality of water surfaces on both flood and ebb portions of the tidal cycle, are invalid. The results indicate that velocity via discharge partly controls the rate of stage rise in the creek system. This reverses the causal direction emphasized by the continuity model approach, where the rate of stage rise is regarded entirely as an independent variable controlling velocity.