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 off southern New England, shows the composition and terrain of the seabed, and provides information on sediment transport and benthic habitat. During July-August 2008 NOAA completed hydrographic survey H11922 west of Gay Head, Massachusetts, in Rhode Island Sound and during July and September 2010 bottom photographs and surficial sediment data were acquired as part of ground-truth reconnaissance surveys of this area. Interpretations were derived from the multibeam echo-sounder data and the ground-truth data used to verify them. For more information on the ground-truth surveys see http://quashnet.er.usgs.gov/data/2010/10033/ and http://quashnet.er.usgs.gov/data/2010/10005/