You want to gain a Jubilee indulgence. That’s great. There’s one problem. You noticed that your surrounded by water and there doesn’t seem to be any floating cathedrals or churches anywhere nearby. This is the dilemma of people who work on ships and even those who are on cruise vacations.
But its the Catholic Church to the rescue. In the Paenitentiaria Apostolica (given in Rome on November 1, 1999) there is a way to receive the indulgence while on a ship. All that you have to do is pray the Our Father and Apostles Creed before a religious image. You also need to renounce all sin and have the intention to receive communion and go to confession as soon as possible. Of course, prayers for the Pope’s intentions should be made and that is normally an Our Father and a Hail Mary.