A mathematical model of diffraction by breakwaters in random waves

This report gives details of a method to predict diffracted wave heights in the lee of a breakwater for random waves. It uses a technique whereby the diffraction coefficients for unidirectional monofrequency wave components are combined according to a specified incident frequency spectrum and directional spread. An example of its application, and effect, is given for a breakwater gap. Some illustrations of the use of the method for the production of diffraction diagrams are provided for island breakwater and breakwater gaps.