When Germany planned to put wind energy plants at offshore locations in the North Sea and the Baltic Sea, the need for additional information on the environmental conditions arose. Therefore, three different research platforms were installed on three remote locations where future offshore wind farm projects were to be realized. The third one is FINO3, located in the North Sea about 80 km off the island of Sylt. In this shallow water region the wind farm Dan Tysk is currently under construction. This research platform is built on a monopile foundation and provides a working platform of 13 x 13 m² in size, a measurement mast with a top level of about 100 m above mean sea level and a helicopter platform for access of scientific and technical personnel. The research conducted ranges from meteorological and sea state measurements to biological observations and studying offshore foundations and structural performance. In this study the differences between the loads from design assumptions and the actual loads on the existing structure are to be analyzed. Therefore, a monitoring system was installed on FINO3 that records the acceleration at three different heights. From these the displacement of the structure is computed and analyzed with respect to Eigen frequencies and Eigen modes. The displacement also enables us to model the platform and to find the local stress factors at critical parts, for example at welds, holes or mountings. With the local stress factors a real load spectrum is available for a durability analysis. With FINO3 we have access to a well-equipped and public research platform where we gain insight into the structural characteristics of the monopile. The monopile is also free from loads of an operating wind turbine and is only affected by the environment.