work(name removed by moderator)rogress8:
First, do you know of any cruises that offer Catholic mass aboard?
The Catholic Answers cruise
Secondly, If no mass is available on the ship or at port, is it a sin?
No, you are dispensed from your Sunday obligation as long as you make every effort to attend. The are areas of the world that it is almost impossible to find a Catholic church (i.e. China, Middle East, etc.) It is also possible that travel itself (i.e. on planes) can make it impossible to attend Mass.
However you aren’t dispensed of your Sunday obligation if you purposely make your travel plans and schedule such that you will miss Mass (i.e. when making plans, you say “If I fly back on Sunday I don’t have to go to church, so lets do it that way.”)
Lastly, is it better to go to a non-Catholic Christian church then no church at all?
If you are dispensed of your Sunday obligation it would probably be better to pray in private, or with a group of Catholics, watch EWTN or some other Catholic station if available. Unless you are in a country that has some of the Orthodox/valid order churches that the Catholic church does allow you to recieve communion (just make sure that group allows Catholics to receive Communion. Just because the Catholic church allows you to receive in certain Orthodox churches, doesn’t mean that Orthodox church allows Catholics to receive.)
P.S. But next time you might want to check
masstimes.org first to verify there are no churches in a particular country/area you are visiting.
Here is a list of churches in Nassau.