The Ocean Brick System (OBS) is a modular system consisting of hollow concrete precast blocs (10m x 10m x 10m) piled up like cubes and interconnected to create a stiff, light and strong structure which can be used for artificial islands, artificial reefs, elevation of vulnerable low lands, deep water ports, breakwaters and foundation of offshore wind turbines. The paper focuses on the experimental results on the wave loading and the stability of the OBS used as a foundation of the support structure of offshore wind turbines. Diagrams for the prediction of total horizontal forces, vertical forces and overturning moments induced by irregular waves on the OB-structure are derived and verified through additional stability tests and stability analysis.