SCAR Antarctic Digital Database (ADD) Version 7.0. Downloaded 2016-2017 from: http://www.add.scar.org/ Seamless access to Antarctic Sea Mask data applicable to all resolutions. A compendium of three polygon datasets which should display well at all resolutions. The masks were created by subtracting the appropriate resolution coastline polygon dataset from a 50 degree roundel centered on the South Pole. For more information, see ADD_General.txt in this folder.