The morpho-dynamic model presented in this paper finds its application in the large time and length scale prediction of wave-driven along-shore sediment transport. It employs an extended version of the well established one-line concept. The model uses a nonlinear wave-field evaluation projecting the curvature of coastline to the bathymetric topography. A new quasi-perpendicular equilibrium profile is applied. Coastline changes are accounted until a finite distance from the averaged shoreline. The methods employed allow the model computation of high and low angle waves at stronger perturbations from rectilinear coastline. The mentioned bathymetric feedback allows to predict sand wave formation, movement, diffusion and high angle wave instability. The effects of changing wave properties, bathymetric parameters and initial shoreline conditions are investigated by numerical experiments. The formation of sand waves is studied using a random initial shore shape.