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. Bathymetry, originally collected by NOAA for charting purposes, provides a fundamental framework for research and management activities along this part of Rhode Island Sound, shows the composition and terrain of the seabed, and provides information on sediment transport and benthic habitat. Interpretations were derived from the multibeam echo-sounder data collected in Rhode Island Sound. During July 2010, bottom photographs and surficial sediment data were acquired as part of a ground-truth reconnaissance survey of these areas. For more information on the ground-truth survey see <http://quashnet.er.usgs.gov/data/2010/10033/>;.