Nowadays, the need of harnessing renewable and sustainable energies is getting higher. As a maritime country, with about one-third of its territory, is the ocean, Indonesia has a considerable amount of ocean energy including ocean wave energy. Therefore, there’s a need for doing research and development pertaining to ocean wave energy. In this modern era, simulation has become a major and inseparable component of research and development. Hence, as the initial step, we tried to focus on looking for ways to simulate any wave energy converter (WEC) technology. The problem is we don’t have too many resources for research available. Therefore, the research needs to be as inexpensive as possible yet still accurate. So, we tried to make use of any open-source tools as many as possible. In this research, we’re trying to validate the accuracy of the open-source WEC-Sim simulation tool in simulating WEC technology. As research objects for validating, we used some experimental results from National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (SNL). We 3D model the object using Matlab/Simulink (for calculation) and Autodesk 123D Design (as the model for 3D simulations). We use MoorDyn for modeling the mooring dynamics of the object. As the Boundary Element Method (BEM) solver we used Nemoh. Then, we used BEMIO to deliver the results obtained from Nemoh to Matlab for further calculation. The results will then be displayed along with animated 3D simulation in Matlab and will be better viewed including the 3D wave animation using ParaView.