A three dimensional beach model applicable to open sandy coastal environments is presented. The model consists of ten beach stages incorporating erosional and accretionary sequences of beach-surfzone morphody-namic conditions. Each stage is associated with a particular level of breaker wave power. Decreasing breaker wave power produces spatially controlled onshore bar migration, eventual bar welding, beach accretion and reflective surfzone conditions (). Increasing wave power generates beach erosion, dynamically controlled bar-channel formation and dissipative surfzone conditions (stages ). Temporal variations in wave power cause predictable movement through and within the model. The effect of beach gradient (tan ) is considered with regard to the influence on the degree of dissipativeness, edge wave length and cut-off modes, and standing wave length. Steeper coarse grained beaches are more reflective and tend to lower (1, 2, 2') reflective stages; fine sand, low gradient dissipative beaches favor outer and multiple bars reflecting higher stages (5, 5' and 6); with low to moderate gradient, medium sand beaches potentially encompassing the entire spectrum of beach stages presented in the model.