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 character and terrain of the seabed, and provides information on sediment transport and benthic habitat. During April-May 2009 NOAA completed hydrographic survey H12007 in the vicinity of Cross Rip Channel in Nantucket Sound off southern Cape Cod, Massachusetts and during June 2011 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.