These data were collected under a cooperative agreement with the Massachusetts Office of Coastal Zone Management (CZM) and the U.S. Geological Survey (USGS), Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center (WHCMSC). Initiated in 2003, the primary objective of this program is to develop regional geologic framework information for the management of coastal and marine resources. Accurate data and maps of sea-floor geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes due to natural or human impacts. The project is focused on the inshore waters of coastal Massachusetts, primarily in water depths of 3-30 meters deep. Data collected for the mapping cooperative have been released in a series of USGS Open-File Reports (http://woodshole.er.usgs.gov/project-pages/coastal_mass/html/current_map.html). The data collected in the study area located in northern Cape Cod Bay Massachusetts includes high-resolution geophysics (bathymetry, backscatter intensity, and seismic reflection), and ground validation (sediment samples, video tracklines, and bottom photographs). The data were collected during five separate surveys conducted between 2006 and 2008 and cover 480 square kilometers of the inner continental shelf. More information about the individual USGS surveys conducted as part of the northern Cape Cod Bay project can be found on the Woods Hole Coastal and Marine Science Center Field Activity webpage: 06012: http://quashnet.er.usgs.gov/data/2006/06012/ 07001: http://quashnet.er.usgs.gov/data/2007/07001/ 07002: http://quashnet.er.usgs.gov/data/2007/07002/ 07003: http://quashnet.er.usgs.gov/data/2007/07003/ 08002: http://quashnet.er.usgs.gov/data/2008/08002/