protocol access inland waterwai mutual access grant contract parti inland waterwai case rhine danub contract parti step reach simultan object equal access freedom establish area inland waterwai arrang ensur reciproc equal access inland waterwai territori contract parti contract parti elabor intern organ concern januari take account oblig relev multilater agreement relev acqui inland waterwai appli entri forc agreement efta state time access commun inland waterwai efta state obtain equal access articl regul eec april oj adapt purpos agreement applic inland waterwai vessel efta state brought servic januari state obtain access inland waterwai commun