Finland started a move to international symbology in 2003 with the revision of the coastal charts for the Gulf of Finland . Traditional Finnish charts are gradually replaced by modern INT charts. The transition to international symbology means changes in colours, symbols and the coordinate system. The new symbology has been adopted by the International Hydrographic Organisation (IHO) as an international standard. The national coordinate system KKJ is replaced by WGS-84. Traditional charts are updated as usual until the revision of the whole chart portfolio has been completed.