Single-beam bathymetry data along with DGPS navigation data was collected as part of the U.S. Geological Survey cruise A-1-00-SC. The cruise was conducted from Port Hueneme, California, to the Mexican border from June 5 to June 29, 2000. The chief scientists were Chris Gutmacher, Stephanie Ross, Brian Edwards all from the USGS Coastal and Marine Geology office in Menlo Park, CA. The purpose of this cruise was to identify and map active and potentially active faults, folds, and submarine slide-prone areas that may threaten densely populated areas of Southern California. This survey was also taken to determine the pathways through which sea-water is intruding into aquifers of Los Angeles County in the area of the Long Beach and Los Angeles harbors. The geophysical source was a Knudsen 12 kilohertz (kHz) 320B/R echosounder. These data are reformatted from space-delimited ASCII text files located in the Coastal and Marine Geology Program (CMGP) InfoBank field activity catalog at http://walrus.wr.usgs.gov/infobank/a/a100sc/html/a-1-00-sc.meta.html into MGD77T format provided by the NOAA's National Geophysical Data Center(NGDC). The MGD77T format includes a header (documentation) file (.h77t) and a data file (.m77t). More information regarding this format can be found in the publication listed in the Cross_reference section of this metadata file.