Benthic data were aggregated from multiple sources to create a baywide record of seabed material in the Chesapeake Bay. Habitat polygons are classified with an adaptation of the Coastal and Marine Ecological Classification Standard (CMECS) Substrate Component (SC). Source data were collected during the interval 1842-2014. Because of potential temporal changes in bottom conditions and deficiencies in survey methodology, benthic habitat characterizations may be in error in some areas. These are, however, the best data currently available. This is a subset of an original dataset which may be found here: http://ftp.ncbo.cgclientx.com/ecoscience/Chesapeake_Bay_Coastal_and_Marine_Ecological_Classification_Standard_CMECS/Metadata/MD_Bay_Bottom_Survey/. This dataset contains only acoustic (SONAR) surveyed data for Maryland and Maryland Bay Bottom Survey data. The NOAA Chesapeake Bay Office makes no warranty, expressed or implied, as to the use or appropriateness of Spatial Data, and there are no warranties of merchantability or fitness for a particular purpose or use. The information contained in Spatial Data is from publicly available sources, but no representation is made as to the accuracy or completeness of Spatial Data. The NOAA Chesapeake Bay Office shall not be subject to liability for human error, error due to software conversion, defect, or failure of machines, or any material used in the connection with the machines, including tapes, disks, CD-ROM's or DVD-ROM's and energy. The NOAA Chesapeake Bay Office shall not be liable for any lost profits, consequential damages, or claims against the NOAA Chesapeake Bay Office by third parties. The liability of the NOAA Chesapeake Bay Office for damage regardless of the form of the action shall not exceed any distribution fees that may have been paid in obtaining Spatial Data.