Sea dikes are of crucial importance for the defense systems of low-lying coastal areas in countries such as Germany, The Netherlands, Denmark, etc. As sea dike breaching induced by storm surges is regarded as one of the main causes of coastal flood disasters, reliable predictions of both the breach initiation, formation and breach development is urgently needed. Although a simple preliminary model for the simulation of sea dike breaching initiated from the seaside was developed ( Stanczak et al., 2006), its limitations showed the necessity for further research and for the development of a more detailed model. This paper therefore provides a summary of the results of laboratory experiments on the erosion of grass and clay revetment of a sea dike induced by breaking wave impact and describes the new detailed computational model, including an uncertainty analysis.