The ESRI Countries 2014 was the primary source for the Maritime Boundaries v9 baseline. The coastline was extracted from the ESRI Countries 2014 and then combined with reefs data extracted from Coral Reef Distribution UNEP for the countries where reefs were fundamental for the correct calculation of the maritime areas, as intended by the coastal state. Several other fixes were made to the coastline to ensure that the coastline could be used as an appropriate normal baseline for the drawing of the multiple Maritime Boundaries areas.

More information: http://www.marineregions.org/eezmethodology.php