In July and September of 2008, the U.S. Geological Survey (USGS) conducted geophysical surveys to investigate the geologic controls on island framework from Ship Island to Horn Island, MS, for the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility project. This project is also part of a broader USGS study on Coastal Change and Transport (CCT). This report serves as an archive of unprocessed digital Chirp sub-bottom profile data, trackline maps, navigation files, Geographic Information System (GIS) files, Field Activity Collection System (FACS) logs, observer's logbook, and formal Federal Geographic Data Committee (FGDC) metadata. Gained (a relative increase in signal amplitude) digital images of the sub-bottom profiles are also provided. Refer to the Acronyms page for expansion of acronyms and abbreviations used in this report.