This paper adopts Genetic Algorithm (GA) -driven optimisation framework to solve the design optimisation problem of an autonomous underwater vehicle that aims to minimise the delivered power under the constraints on the geometric parameters that define the hull shape. The GA and computational fluid dynamics (CFD) solvers are seamlessly integrated into a single code so that it becomes an effective computational tool for optimisation. Adopting a hull and a ducted propeller, for which some experimental data are available for CFD validation, the optimisation is done for the shape of the hull for a single velocity, leading to significant reduction in delivered power. The hull shape is described by a 5-parameter axisymmetric form. Delivered power minimisation problem is compared with the corresponding drag minimisation problem of the chosen hull. © 2017 Informa UK Limited, trading as Taylor & Francis Group.