A study on the database system aimed at the prediction of ship's maneuverability has been carried out. The database system covering full-scale ship's performance, hydrodynamic ship model data and ship geometry is presented. The full scale ship maneuvering performance data and model hydrodynamic data are analyzed here. The results are explained by comparison with series ship model test data. It is pointed out that the use of the database system has limited accuracy if only ship's main particulars are used for the database access. To remedy this situation, an idea of using a type ship concept for improvement of the maneuverability prediction is proposed.