Abstract— The object of this paper is to investigate the influence of wave-current interaction on a tidal turbine. An experiment at Norwegian Marine Technology Research Institute (MARINTEK) has been carried out, and a CFD analysis has been performed in order to enhance the understanding of the wave induced loads on the tidal turbine. These loads are known to be the governing forces and it is therefore of great importance to predict them accurately. The CFD results are found to be trustworthy with calculated values close to experimental data. In addition to the wave-induced forces, the wake characteristics and wave influence on the wake are investigated. Results from Blade Element Moment Theory (BEM) are also compared to validate the accuracy of this method. CFD is a powerful tool if used properly, but it is computationally expensive, especially when dealing with complex geometry like a tidal turbine. A high performance computer (HPC) has been used to carry out the transient CFD wave-current simulations in order to obtain reliable results within reasonable time.