The design of crest walls is often based on empirical formulations, physical model tests, numerical models and a fair amount of expert judgement. The present work validates the prediction of wave induced forces on the front face of crest walls on top of composite breakwaters in the numerical model OpenFOAM. The results show that OpenFOAM is able to capture the shape and order of magnitude of the force events caused by non-breaking and heavily breaking waves. In addition, a calibrated model predicts the highest wave induces forces caused by breaking waves with errors lower than 20%.