The ship
The ship seen in overhead shots, isn't that this one. These links go to two different sites but show the same ship. The second site is in swedish.
http://www.ferry-site.dk/ferry.php?id=7904891&lang=en
http://www.faktaomfartyg.nu/prinsesse_ragnhild_1981.htm
Formerly a Norwegian ferry. I think in the scene at the beginning of the film, where the newlyweds are standing at the docks looking at the ship, we see a different ship.