Standard levelling techniques, carried out daily for 13 days during a semi-lunar tidal cycle, were used to obtain cross sectional profiles perpendicular to sandwave crestlines on a drying bank. The results were used to study bedform movement and to infer internal structure (Langhorne 1982). Sedimentary evidence of such structures, or master bedding, was verified by box coring. The conclusions, compared with those obtained on previous occasions at a subtidal site, indicate the difficulties of distinguishing the apparently contrasting hydrodynamic regimes using structural criteria. This has important implications for the interpretation of palaeo-environments from ancient sediment-tary structures.