The objective of the Master’s thesis is to compare different NWT in terms of efficiency and accuracy. Comparisons will be achieved on a set of experimental tests already conducted in ECN. Different types of wave fields will be studied, with an increasing degree of complexity: from regular waves to unidirectional irregular waves. In addition, the wave conditions will cover mild sea conditions up to extreme sea states, exhibiting breaking events. Each numerical model has a different methodology to take care of breaking event and it is one particular focus of the Master’s thesis.