This project frames in the MAST III programme within the Fourth Framework (1994-1998) of the European Community. Ten partners out of seven European countries participated in the OPTICREST project. Ghent University was project co-ordinator. Four main objectives have been put forward: 1) Provide improved design rules for the crest level design of sloping coastal structures, mainly based on prototype data and supported by physical scale model results. 2) and calibrate physical scale models with prototype data for wave run-up. 3) Calibrate numerical models with prototype data and physical scale model results for wave run-up. 4) Improve existing wave run-up monitoring devices plus ancillary software and install on two prototype coastal structures.