In order to make marine hydrokinetic (MHK) devices competitive in the energy market, developers need measurements to validate numerical models, improve performance and reliability, and establish standards. Sandia provides testing and analysis expertise to aid field measurement campaigns and demonstration activities. We are currently working with the National Renewable Energy Laboratory and Pacific Northwest National Laboratory to develop test plans and instrumentation packages for a field measurement campaign. Sandia will design, test, and install a fiber Bragg grating sensor to measure strain and dynamic load response on device components. The measurements from these sensors will be used to validate and improve several mid-fidelity models.