This paper presents a novel Ocean Sentinel instrumentation buoy that the Northwest National Marine Renewable Energy Center (NNMREC) is developing with AXYS Technologies for the testing of wave energy converters (WECs). NNMREC is a Department of Energy sponsored partnership between Oregon State University (OSU), the University of Washington (UW), and the National Renewable Energy Laboratory (NREL). The Ocean Sentinel instrumentation buoy is a surface buoy based on the 6-meter NOMAD (Navy Oceanographic Meteorological Automatic Device) design. The Ocean Sentinel will provide power analysis and data acquisition, environmental monitoring, as well as an active converter interface to control power dissipation to an on-board electrical load. The WEC under test and the instrumentation buoy will be moored with approximately 100 meters separation, connected by a power and communication umbilical cable. The presentation of the paper will include the deployment and example testing of wave energy devices using the Ocean Sentinel instrumentation buoy.