Computational methods have been used in marine engineering for a long time to design and optimize marine vessels, from yachts to offshore platforms. It is just that those traditional computational methods are often not considered as “proper” CFD (Computational Fluid Dynamics) - because they are based on potential flow theory and empirical correlations. While simpler methods may be suitable to optimize a single component on its own, the strength of CFD lies in its ability to account for interactions between all components of a system (e.g. hull, propulsion and steering system, and other appendages on a ship) in full scale and under realistic initial and boundary conditions, including fluid-structure interaction. CD-adapco has been at the forefront of this development and it is no surprise that its software is most widely used in marine industry. This report presents some CFD-applications to solving real world problems by our customers, ranging from classification societies to small consulting companies. It gives an overview of where CFD is being used today and the feeling for where this development will lead us in the future. There is no doubt that CFD will play an ever increasing role in the optimization of marine structures to increase the fuel efficiency, improve safety for passengers, crew and payload, and reduce pollution of environment.