Longitudes are given to the nearest 0.000278. Latitude and longitude values are specified in Decimal Degrees. The horizontal datum used is North American Datum 1983. The ellipsoid used is GRS1980. The semi-major axis of the ellipsoid used is 6378137.
Areal water features in the United States.
The representation of the entity in the data. The size of the shape in coverage units. The perimeter of the shape in coverage units. Value Definition Bay or Estuary or Ocean A body of salt water. Canal An artificial open waterway constructed to transport water, to irrigate or drain land, to connect two or more bodies of water, or to serve as a waterway for water craft.