Wind turbine has gained a keen interest in the field of research but its low efficiency due to low working fluid density triggers the need for upgradation. However, this technology will get a boost if the factor of low density fluid is eradicated. This paper is intended towards the study of performance of the same design of Savonius wind turbine when operated in high density water. The density of water is approximately 1000 times more than air. In the present study, the performance of a two bladed Savonius wind turbine and a Savonius water turbine have been analyzed both experimentally and with the aid of Computational Fluid Dynamics (CFD) using Ansys 19.0, keeping the maximum power content (Pmax) of the fluid-stream constant. Coefficient of power (Cp) is one of the deciding factors for superiority of the turbines one over the other. For the study, three cases of power contents viz. 0.61 W, 6.2 W and 16.45 W have been considered. The results obtained suggest that the Savonius water turbine with the highest Cp value of 0.343 is dominant over Savonius wind turbine. The effects of tip speed ratio and Non-dimensional factor (γ) on performance of both the turbine kinds have also been studied.