The purpose of this thesis is to reduce the computational time spent in order to evaluate the extreme events that will be crucial for the design process of the WEC. The analysis will be performed on IWSEC, considering the Environmental Condition of Pantelleria. In the first part is presented the theory of the probabilistic models useful for definition of the Environmental Contour. In the second part a method of analysis for the omnidirectional EC is chosen for the case study and the same process is repeated considering the direction of the wave. A comparison between the proposed method and the Standards is carried out.