Two decoupled PID controllers and a state feedback pole placement control configuration have been designed for the navigation and propulsion systems of CyberShip II, a scale model of an oil platform supply ship. These control structures have parameters that need to be tuned to improve their performance. The values of these parameters have been optimised using genetic algorithms. The performance of these controllers has been analysed through computer-generated simulations based on a non-linear hydrodynamic model of CyberShip II. The robustness has been evaluated through simulation in the presence of environmental disturbances. Subsequently, the optimised controllers have been tested in the real plant and the results are shown.