As a result of the increase in fuel costs and the new gasoil exhaust emission rules, ship owners are forced to take measures nowadays in order to reduce fuel consumption and exhaust emission. Among the different types of vessels, fishing vessels deserve particular attention due to their poor propulsive efficiency. The fishing fleet is indeed old and was designed at a time when the focus was not on resistance reduction or propulsive efficiency but on the catch. Hence these vessels have a high block coefficient and propulsive systems that are not wake-adapted. To reduce fuel consumption, the hull shape can be modified but such is not the case for existing vessels. Nevertheless retrofitting these vessels in order to modify the propulsive system and adding some appendices like bulbous bow or bilge keels is possible. Among fishing vessels, trawlers are the most complicated vessels because they have to operate at two very different speeds, i.e. the propulsive system has to be adapted for two very different conditions.

In this paper, we will focus on a 42m long trawler. Different types of propulsive systems will be considered: fixed pitch propellers, ducted propellers, controllable pitch propellers and twin-screw propellers. Different methods such as the statistical method, the potential method and the finite volume method will be used. Firstly, the aim will be to compare the different propulsive systems in order to select the best solution for the present case. Secondly, the different codes used are also compared.