National Ocean Service (NOS) Cartographic Codes for Bottom Character in the Gulf of Maine region (NOSGOM shapefile)
These data were collected by the National Ocean Service (NOS, formerly the U.S. Coast and Geodetic Survey) for the purpose of charting the coastal waters and navigable waterways of the United States.  Data collected prior to 1965 were digitized from the final survey plots.  All other data were digitized in the field …