From August 16 to 21, 2018, the U.S. Geological Survey (USGS) conducted a geophysical survey to investigate the geologic controls on barrier island evolution and medium-term and interannual sediment transport along the sand berm constructed in 2011 (offshore, at the northern end of the Chandeleur Islands, Louisiana) as mitigation of the Deepwater Horizon oil spill. This investigation is part of a broader USGS project, which seeks to better understand barrier island evolution over medium time scales (months to years). This publication serves as an archive of unprocessed, digital chirp subbottom data, survey trackline map, navigation files, geographic information system (GIS) data, and formal Federal Geographic Data Committee (FGDC) metadata. Processed subbottom profile images are also provided. The archived trace data are in standard Society of Exploration Geophysicists (SEG) SEG Y revision 0 format (Barry and others, 1975) and may be downloaded and processed with commercial or public domain software such as Seismic Unix (SU). These data are available for viewing using GeoMapApp (http://www.geomapapp.org/) and Virtual Ocean (http://www.virtualocean.org/) multi-platform open source software. In addition, the SEG Y files can be downloaded from the USGS Coastal and Marine Geoscience Data System (CMGDS, https://cmgds.marine.usgs.gov).