Finland first adopted the international symbology (INT) in the coastal charts of the Gulf of Finland in 2003. New blue nautical charts replace the traditional green charts.
The transition to international symbology has meant changes in colours, symbols and the coordinate system. The new chart symbology is based on the IHO's international standard. The national coordinate system (KKJ) is replaced by the international system WGS-84.
During the transition period, the green nautical charts are updated as normal, until all nautical charts have been replaced.