a series of ro-ro ferry or high-speed passenger craft crossings operated so as to serve traffic between the same two or more ports, or a series of voyages from and to the same port without intermediate calls, either: (i) according to a published timetable; or (ii) with crossings so regular or frequent that they constitute a recognisable systematic series, merereis avalikustatud reisigraafiku alusel või nii korrapäraselt või sageli, et avaldub tema ilmne regulaarsus