Abstract: Coastal regions play a prominent role in the sectors of energy, tourism, fisheries, climate regulation and world trade. In light of these benefits, these regions are more densely populated with 40% of the world’s population living within 100km of the coastline.  However, due to the increased effects of climate change on oceans in the form of increased sea-levels, an increased frequency of extreme wave events and an increased magnitude of wave height predictions, coastal regions are increasingly under threat. As such, the accurate design of coastal structures is of significant importance. Yet, the complexities associated with coastal waves present many challenges in their accurate numerical modelling. This work investigates the state-of-the-art numerical wave models, with a particular emphasis on Simulating WAves till SHore (SWASH). SWASH is utilised to simulate regular and random fully nonlinear waves propagating over a range of bathymetries. The results of these simulations are compared to experimentally generated data to establish the scope of accuracy of the model and its ability to capture key physical effects including wave shoaling, wave refraction and higher-order effects. Particular emphasis is given to SWASH’s ability to capture wave breaking, both with regards to the correct point at which breaking is initiated as well as an accurate dissipation of energy subsequently. Moreover, modifications to the boundary conditions in SWASH are proposed which seek to overcome the limitations of the numerical model.