The U.S. Geological Survey (USGS), in cooperation with the National Oceanic and Atmospheric Administration (NOAA), is producing detailed geologic maps of the coastal sea floor. Bathymetric and sidescan-sonar data, originally collected by NOAA for charting purposes, provide a fundamental framework for research and management activities along this part of Block Island Sound, show the composition and terrain of the seabed, and provide information on sediment transport and benthic habitat. During June 2012, bottom photographs and surficial sediment data were acquired as part of a ground-truth reconnaissance survey of this area. Interpretations were derived from the multibeam-echosounder, sidescan-sonar, sedimentary, and photographic data collected in Block Island Sound. For more information on the ground-truth survey see <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2012-002-FA>;.