Authoritative Federal gazetteers such as the Geographic Names Information System (GNIS; https://geonames.usgs.gov/pls/gnispublic/) and the GEOnet Names Server (GNS; http://geonames.nga.mil/gns/html/) generally provide single-point locations for named features, because the primary function of these gazetteers is to standardize geographic name usage. Many geospatial information services, however, would be improved if the authoritative place names from these gazetteers were associated with polygons representing the actual spatial extents of the features in question. The U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) is compiling and processing shapefiles to facilitate the retrieval of georeferenced information resources related to named oceans and seas, undersea features, coastal features and waterways, and relevant administrative areas including the U.S. Exclusive Economic Zone (EEZ) and Coastal Zone Management Program (CZMP) counties. Geospatial information systems with the capability to search user-defined, polygonal geographic areas will be able to utilize these shapefiles or secondary products derived from them, such as linked data based on well-known text (WKT) representations of the individual polygons within the shapefiles. The precision of geographic searches in any system that uses these polygons will depend, of course, on the nature of the search algorithm.

Version 1.1 of this report provides a shapefile for 311 undersea features from all major oceans and seas, along with a linked data representation of 299 of these features and their spatial extents. Features were selected in two phases as described in "Data Sources". A previously released report provides a shapefile for CZMP counties (Hartwell and others, 2013).