DCW-GMT - The Digital Chart of the World for GMT 6 or later

Version 2.1.2 Released August 11, 2023

DCW-GMT is developed and maintained by

Paul Wessel, SOEST, University of Hawai'i, Honolulu, HI, USA.
Federico Esteban, Consejo Nacional de Investigaciones Científicas y Técnicas: Buenos Aires, Argentina.
Eduardo Suarez, Facultad de Ciencias Astronomicas y Geofisicas - UNLP, Argentina (deceased).

The Digital Chart of the World (DCW) is a comprehensive 1:1,000,000 scale vector basemap of the world. The charts were designed to meet the needs of pilots and air crews in medium-and low-altitude en route navigation and to support military operational planning, intelligence briefings, and other needs. For basic background information about DCW, see the Wikipedia entry.

DCW-GMT is an enhancement to DCW in a few ways: (1) it contains more state boundaries (the largest 8 countries are now represented), and (2) the data have been reformatted to save space and are distributed as a single deflated netCDF-4 file. The raw files used to build dcw-gmt.nc came from the Princeton University Digital Map and Geospatial Information Center, accessible via website http://www.princeton.edu/~geolib/gis/dcw.html; however, the DCW access seems to have disappeared. Your best bet for more information is WikiPedia. DCW-GMT is released under the GNU Lesser General Public License.


  1. If you are building GMT from source then you should set the parameter DCW_ROOT in the cmake/ConfigUser.cmake to point to the directory where dcw-gmt.nc has been placed. If you add this file after GMT installation you can always have GMT find it by placing it in your user ~/.gmt directory or setting the DIR_DCW parameter in the gmt.conf settings.

    Availability of DCW-GMT data

    The latest data files are available below; details on the changes are described in the ChangeLog. For GMT versions 6.1.1 or later, you may download one of these files via ftp or http:
    1. FTP: DCW-GMT polygons for GMT in netCDF 4 format (gzipped tar archive).
    2. FTP: DCW-GMT polygons for GMT in netCDF 4 format (zip archive).
    3. HTTP: DCW-GMT polygons for GMT in netCDF 4 format (gzipped tar archive).
    4. HTTP: DCW-GMT polygons for GMT in netCDF 4 format (zip archive).

    Last update August 11, 2023 by Paul Wessel