Full mission simulators are increasingly used for crew training and various port design tasks. This chapter describes developments of the tool, as well as the Great Belt East Bridge simulations, which are among DMI's first applications for bridge design. Compared to flight simulation the development and use of ship simulators are still relatively new. Port designers take increasingly advantage of the flexibility and realism of modern ship simulators. A crucial element in ship simulation is of course a realistic reproduction of vessel behaviour. The chapter presents the technical development that significantly influenced the provision of high quality models in modern ship simulators. A basic condition for modelling the manoeuvring of vessels is the physical understanding of flow mechanisms and forces. In addition to the enhanced technical quality of full-mission simulators one major advantage and justification for the use of simulation facilities is the inclusion of the human factor.