The Digital Elevation Model can be obtained as a 32-bit GeoTIFF file, a NetCDF file, a ZIP file containing an ESRI ASCII Grid, or via the web services provided by the THREDDS Data Server (Table 3). These services include:

• OPeNDAP: Open-source project for a Network Data Access Protocol. Use this service to subset and download data directly into OPeNDAP applications. http://geoport.whoi.edu/thredds/dodsC/bathy/gom03_v1_0.html
  
  
• NCSS: NetCDF Subset Service. Use this service to subset and download data as a NetCDF file: A web interface to this service is here: http://geoport.whoi.edu/thredds/ncss/grid/bathy/gom03_v1_0/dataset.html



Table 3. Methods for downloading the bathymetry grid used in developing the digital elevation model for the Gulf of Maine.



File description	FGDC Metadata	View	Download Data
Vertical Datum: NAVD88 Coordinate System: Geographic (lon/lat) Horizontal Datum: NAD83 Resolution: 3 arc seconds (0.0008333°) Format: COARDS/CF-compliant netCDF	text xml html faq		32-bit GeoTIFF File (zipped) (268 MB) NetCDF File (zipped) (269 MB) ESRI ASCII Grid (zipped) (495 MB) THREDDS Data Server Services