EM300 and EM3002D multibeam data were collected between 10-29 October 2006 aboard NOAA Ship Hi'ialakai at Brooks Banks, St. Rogatien Bank, and West Nihoa Island in the Northwestern Hawaiian Islands during cruise HI-06-12. These multibeam data were collected using SAIC ISS-2000 software in the Generic Sensor Format and processed using SABER editing software. Surface sound velocity values were supplied by a Seabird SBE-45 MicroTSG and a SBE-38 remote temperature probe. Sound velocity corrections from a Seabird 911 CTD sensor and motion corrections from a POS-MV vertical reference were applied to the data in real time. Predicted tides were applied to the data in real time using tide zoning and predicted tides supplied by NOAA's National Ocean Service Center for Operational Oceanographic Products and Services (CO-OPS). Horizontal accuracy is 20m (no differential GPS correctors applied), vertical accuracy is depth dependent (~1% of water depth), WGS84 datum. These data are not to be used for navigation. Depths mapped range from 30 to 1000 m. Concurrent mapping was done by the R/V AHI in water depths ranging from 30-150 m with the data set being AHI-06-12; metadata for AHI-06-12 are submitted separately.