The EMACOP (Marine Energies in coastal regions and harbours) project aims at studying the feasibility and relevance of combining wave energy converters (WEC) with coastal structures such as dikes. In the framework of this project, we present in this paper a complementary use of a potential code and a SPH code for the study of a bottom-mounted pitching flap. The developed tools are applied to Bayonne and Saint Jean de Luz site in order to evaluate mean annual power production and estimate maximum loads experienced by the flap under extreme wave conditions. Regarding the power matrix assessment, the specificity of the study is in the use of symmetry considerations to model the behaviour of the flap in front of the dike. The advantage of coupling with the dike compared with an isolated configuration on WEC performances is analysed and main uncertainties are mentioned. In parallel to the WEC performance assessment, SPH computations have been performed to estimate extreme loads experienced by the flap. The influence of wave breaking inception and tide level on impact loads is addressed, and 3D effects are highlighted.