The growing interest in renewable energy sources has driven the development of technologies such as hydrokinetic turbines, which are capable of harnessing the energy available in marine currents within underwater environments. In this context, the present study experimentally investigated the influence of different trailing-edge geometries, which correspond to the region of the blade where the flow leaves itssurface, on the performance of Savonius-type hydrokinetic turbines. Four turbine configurations were evaluated: a reference turbine, a turbine equipped only witha support structure for trailing-edge installation, a turbine fitted with a rectangular trailing edge, and a turbine fitted with a serrated trailing edge. Experimental tests were conducted in a water channel at flow velocities of 0.3 m/s and 0.4 m/s. Turbine torque and rotational speed were measured, from which the dimensionless powerand torque coefficients were calculated as a function of the tip speed ratio. The results showed that all configurations exhibited behavior consistent with that typicallyobserved for Savonius rotors. The introduction of the support structure resulted ina reduction of more than 40 percent in the maximum power coefficient compared to thereference turbine, highlighting the impact of geometric modifications on the flow around the rotor. The installation of trailing edges enabled a partial recovery of thisperformance, with the serrated configuration achieving the best results among the modified geometries, providing gains of up to 44 percent relative to the turbine equipped only with the support structure and outperforming the rectangular trailing edge at both flow velocities analyzed. Nevertheless, none of the modified configurations was able to surpass the performance of the reference turbine. The results contribute to a better understanding of the influence of trailing-edge modifications on Savoniushydrokinetic turbines and provide a promising basis for the development of more efficient hydrokinetic turbine configurations for underwater applications.