This paper describes development of the mathematical model simulating ocean performance of an offshore wave energy point absorber device-AquaBuOY. The AquaBuOY is the next generation of the technology, based on the IPS point absorber system and the hose pump, both of Sweden. AquaEnergy Group Ltd., USA, is developing the system in cooperation with RAMBOLL, Denmark. In March 2003 the Danish Energy Authority awarded a grant for a design study that includes development of the numerical model for the AquaBuOY operation, experimental testing and design optimisation. The scale model tests will be carried out at Aalborg University, Denmark in order to optimise the device design, operation and installation configuration with the goal of minimising s...