I might be wrong, but I believe Princess is the only line that still provides weddings on board. I think with the other cruise lines, you can renew vows or get married on an island. My friends checked into a couple of years ago, they went with Celebrity and married on St. Thomas. She told me that Princess was the only one that would perform the wedding on board, but you had to book it through another company. If you'd like, I can email her and find out who it was and why she decided to go with getting married on St. Thomas instead. I believe it was the cost, but I'd be happy to try to find out for you. Best wishes!
You can get married on the ship. It will be by a wedding coordinator unless you make arrangements for an official from the religion of your choice. Princess is the only cruise line where the Captain can marry the couple. You need to talk directly to the wedding department. Carnival's is 800-933-4968. You need to know what ship and date you want. You may have to have the cruise booked before the wedding department starts working with you, but you need to call them first to make sure they have openings for the date you want on the Glory. They will only do so many weddings in one day.
If you are getting married on a cruise, then the wedding must take place in a port of call. The marriage must be registered in a specific jurisdiction, so you can't be married at sea in international waters.
The only exception to this rule is the Province of British Columbia Canada - there you can be married at sea as long as you are with in the territorial waters. If you are sailing on an Alaskan Cruise out of Vancouver BC Canada, that would be one option.
My daughter got married January 2006 in Jamaica. We were on the Carnival Triumph which did have onboard weddings at Ports of Call. We found it was cheaper to do the wedding onshore. We got beautiful photos. The wedding was at Ruins at the Falls in front of their waterfall. We had a wedding coordinator who did all of the work for us. (getting the married license, decorating, minister, etc) we also had pictures taken on the ship so we had it both ways. Also celebrated at dinner with all 24 of us in our wedding clothes with champagne and everyone congratulating the bride and groom. Very special, wouldn't do it any other way.
I have attended two weddings on the Carnival Victory. Both took place at 1PM on the ship in Miami the day of cruise departure. The wedding will be held in one of the lounges on the ship. Depending on the size of your wedding group and how many other weddings they have the day of your departure will determine which lounge. Both weddings I attended were small about 30 people or less. The room is set up to form an aisle coming in from the lounge door, leading to where the bride and groom will stand. On each side where they stand is white column stands with flowers. The guest chairs are on each side. The ships photographer will be taking all the traditional pictures. The officiate will perform the ceremony (unless you have made arrangements for a specific pastor, reverand, etc. The ceremony itself is probably only about 20 minutes. What happens next is dependent on which wedding package you buy. One wedding we stayed in the same lounge and had a champagne toast and cake. The other wedding was larger and they bought the one hour reception. For that we moved to the Disco lounge where they had hot and cold hordourves, and one hour of cocktails. They had decorations and ice sculpture set up in the Disco.
Warning: The photographer can get carried away after the ceremony taking up your time wanting to take way too many pictures. Ofcourse they are hoping you will buy them all. If you find this happening, politely tell them "Thank You, that's enough"
Hope this helps.