Model testing is the well-recognised method to evaluate final designs of F(P)SO systems. In concept phase, however, the designer has to rely on computational tools. Moreover F(P)SO systems are nowadays designed for water depths up to 2000 m. For a water depth of more than 1000 m the existing model basin facilities have insufficiënt water depth. For the full water depth, including a vertical current distribution, a synthesis between model tests and computational tools have to be made to evaluate the final designs. A computer program on fully integrated dynamics of turret moored F(P)SO systems has been developed recently. By model testing of the systems at the available water depths the results of model tests can be tuned with the results of the computer program. By means of the tuned computer model the final design at deeper water may be carried out. Furthermore, the computer program can be used to optimize the system and to enhance the safety of the design by applying numerous combinations of extreme weather conditions in order to discern the most severe weather condition. • In this paper the state-of-the-art computational tooi for the fully integrated dynamics of a turret moored F(P)SO system will be described and some examples of computations will be shown. The mentioned aspects of the design so far concerns the mooring loads and the general tanker behaviour. Computational tools conceming safety aspects of green water loading on the turret housing and process equipment, however, need a different approach and will also be discussed.