A novel manufacturing approach similar to filament winding has been developed and automated and is able to produce the Composite Material Marine Current Turbines (CMMCT), which have significant advantages over traditional designs. This paper presents numerical results to investigate the performance of these turbines. The numerical approach was performed using Computational Fluid Dynamics (CFD) in a free stream of water with various hydrodynamic flow conditions. Static torque, extracted power and power coefficient were calculated at different rotating speeds in a free stream with various hydrodynamics flow conditions. The power coefficient of CMMCT was compared to that of traditional current turbines. The calculated results will provide a fundamental understanding of the impeller as a water turbine, and this design method is used to shorten the design process and improve the water turbine's performance.