It is proposed the new type turbine for OWC that is consists of Wells and Impulse turbines. Wells and Impulse rotors are set parallel for high efficiency and starting characteristics. This paper presents the results of the numerical simulations in steady flow condition. The maximum efficiency is obtained at the low flow coefficient that is fitted to the high speed operation. The variation of efficiency with flow coefficient is small for large flow coefficient that advantages to the starting characteristics. The split duct is designed to fit the flow coefficient at the maximum efficiencies of Wells and Impulse turbines. It is pointed out that the geometry of the split duct is important to improve the turbine performance.