A 1:6 scale physical model of the Sandia/DOE Reference Model 2 (RM2) cross-flow hydrokinetic turbine was tested in a large cross-section tow tank at the Center for Ocean Renewable Energy (CORE) at the University of New Hampshire (UNH). Performance data for the RM2 turbine were obtained at sufficiently high Reynolds number; to be used to investigate the accuracy of hydrokinetic turbine performance models, such as CACTUS, and other numerical models. Turbine torque, drag and angular velocity were synchronously measured with inflow speed and wake velocities. The influence of strut drag on turbine performance was also investigated, by replacing the streamlined struts with circular cylinders to deliberately increase strut drag. The data provide insight into the physics of hydrokinetic cross-flow turbines, including the importance of blade strut drag on turbine power output, which will inform investigations on the present limitations of the CACTUS model and potential modifications to improve its accuracy. The strut drag investigation will also give turbine designers some perspective on the need to mitigate parasitic strut drag effects to improve rotor efficiency. Turbine drawings , test plan  and reduced data and processing code  are publicly available via figshare DOIs. We encourage MHK developers and DOE partners to use the experimental data for validation of numerical models.