In the current scenario, the consumption of fossil fuels and the energy obtained by means of nuclear fission are questioned due to all the problems they concern. One of the best answers to that issue is the use of renewable energies and, amongst them, Oscillating Water Column (OWC)-based energy converters. These devices transform the mechanical energy of the waves into electrical power by means of a capture chamber and a turbo-generator module. However, this technology is still under development, being the capture chamber modeling one of the challenges when dealing with this kind of systems. In this context, the main aim of this study is to model the OWC chamber and to validate this model using in-situ measured experimental results for the particular case of the Mutriku OWC power plant.