A design optimisation procedure for Energy Saving Devices at full scale is proposed. Validation and verification procedures for the numerical open water test simulations were presented. Propeller Boss Cap Fins geometry were parametrically modelled being able to produce various designs ready for automation. An optimisation system framework using a parametric modeller, a flow solver and a high performance computer was described. The functions and physics behind Propeller Boss Cap Fins were analysed and further investigated.