Bathymetry Availability

Using NOAA point soundings   NOAA main bathymetry site       USGS Bathymetry Portal         DEMs on land

MICRODEM requires that depths have negative z values.  You can quickly edit the DEM to multiply the depths by -1.

Spacing Data series Coverage Provider Web Source Notes
5' (~10 km) ETOPO5/1 Entire world, including ocean basins NOAA


Need header for MICRODEM.  The original bathymetry came from the version of DBDBV available at the time ETOPO5 was created.
2' long (lat Mercator factor) Smith & Sandwell Predicted topography Entire world, including ocean basins SIO/NOAA Scripps Ideal for geological base maps 
2' long ETOPO2   NOAA NOAA download GEODAS build a grid (use ASCII XYZ)
1' long GEBCO One Minute Grid Worldwide
Full data or subsets.  netCDF, Geottff, or ESRI ASCII
1' long ETOPO1 NOAA 
30" GEBCO_2014 Grid 
Full data or subsets.  netCDF, Geottff, or ESRI ASCII
30" Merge of SRTM30, Smith & Sandwell, and IBCAO Entire world, including ocean basins   Scripps Get the SRTM version files, with a data file and an ERS header.  Open with MICRODEM which will use GDAL.  You will probably have to edit the header to get the correct SW corner.
  Global Multi-Resolution Topography Data Portal (includes RIDGE data)     MGDS  
  Seamount database     Scripps GMT format
  USGS Coastal mapping (includes lakes)   USGS


Crater Lake, Lake Tahoe, San Francisco, Los Angeles, San Diego, Hawaii, Gulf of Mexico--not all may be supported in MICRODEM
3" to 10' NOAA Design a Grid     NOAA info

NOAA download

US coastal and Great Lakes

GEODAS build a grid (use ASCII XYZ for export).  If you use the G98 format, expect to have to edit the coordinates of the SW corner.

  NOAA Multibeam Viewer and Data Downloader     NOAA  
15" and 250 m NOAA EEZ US coastlines out to 200 nm NOAA NOAA description EEZ data is old; may have to purchase on CD
1' Geographic

250 m Polar stereographic

International Bathymetric Chart of the Arctic Ocean (IBCAO) Arctic Ocean   NOAA Current version requires some modification
15" and 30" Land/sea merge Gulf of Maine USGS USGS Arc, GMT, Matlab and ASCII formats.
7.5" European waters     EMODnet-bathymetry
Get the Arc ASCII.  The 16 bit Geotiff is a colored image, and the 32 bit Geotiff has issues.  Includes Black Sea, Med, North Atlantic, some Arctic.
100 m EEZ grids Alaska, East Coast UNH UNH Get the ASCII format.
3" Land/sea merge Coastal US

Great Lakes Bathymetry


NOAA download

Available on CD ($). 


30 m US Coastal Estuaries Selected estuaries, underwater only NOAA NOAA Includes Hudson River, Chesapeake Bay.  Get USGS ASCII format for MICRODEM
  USGS California  
40 feet Gulf of Mexico  


Random XYZ points
  NOAA soundings     NOAA soundings  
Academic Web Sites Notes on Multibeam Available AHA-NEMO2, Shipboard data web site compiled during R/V Melville NEMO Expedition, Leg 2, D. Fornari, M. Perfit, M. Tolstoy, R. Haymon, D. Scheirer, P. Johnson, G. Kurras, S. White, J. Getsiv, and shipboard scientific and technical party, May, 2000


DeepSeaDawn data  Tsunami grids
MH370 bathymetry and backscatter:

Raw Soundings

Marine geology and geophysics ChesBay seds


Topobathymetric Model for Chesapeake Bay Region - District of Columbia, States of Delaware, Maryland, Pennsylvania, and Virginia, 1859 to 2015 is on the NOAA Coastal website

Last revision 8/20/2018