The area north of the Mokapu Peninsula, adjacent to Kaneohe Marine Corps Base Hawaii (MCBH), has been utilized by the U.S. Navy and Ocean Power Technologies, Inc. (OPT) for wave energy research since 2002. A prototype OPT PowerBuoy is presently deployed at the 30 m water depth offshore of North Beach at the MCBH. The Hawaii National Marine Renewable Energy Center (HNMREC) at the University of Hawaii, under contract with Department of Energy, desires to expand the present test site to water depths of 100 m to allow for the testing of other wave energy devices. Sea Engineering has been contracted by the HNMREC to conduct site investigations in support of the development of the expanded test site. This report presents the results of the multibeam sonar bathymetric survey of the site. The project location is shown in Figure 1-1. An aerial image of the 4.4 km2 proposed test site is shown in Figure 1-2. The test site is 1600 to 2000 m wide and extends approximately 2600 m offshore from the 30 m depth contour to the 100 m depth contour.