What are options if one wants to eat kosher on a cruise?

There are different ways for one to cruise kosher.
1) All-Kosher boats - there is one company that has an all-kosher boat.
Chosen Voyage has been running all-kosher cruises since 2004. While kosher usually refers to dietary laws set out in the Torah, on Chosen Voyage's cruises it is also applied to daily living as practiced by orthodox Jews who are observant of laws pertaining to modesty, prayers and the Sabbath. When the Chosen Voyage is sailing, the ship's business center is converted into a Judaica library and the wine list is replaced with kosher wines. Daily minyans take place in the conference room, and on the Sabbath the lounge is transformed into a synagogue.
Pros: Can vacation in deluxe style while completely observing halacha.
Cons: Have to travel with all Jews
Available by: Chosen Voyage which sails on various small and medium sized cruise vessels.
2)Pre-packaged Kosher Meals - kosher meals are pre-packaged off the ship in a kosher kitchen, frozen and brought to the table sealed in their original containers; kitchens on board are not kosher.
Pros: If fancy food is not important to you,then this is a way you can travel like without the jewish "chevra".
Cons: If your idea of a deluxe vacation includes gourmet food, this is not the path to take.
Available on: Most major "Mega" cruise ships ex. Celebrity Cruises, Holland America, Royal Caribbean
3)Kosher Kitchen on ship - there are various agencies that take over and kasher a kitchen on the ship, they bring in specially selected chefs and mashgiachim and with all that they are able to prepare food that have the standard of a 5-star hotel.
Pro: You can travel with a Jewish chevra as well with a few hundred "other" people and still eat gourmet, lavish, food 3 meals a day.
Con: The halahic issues of kashrut are very complicated on a huge ship that run both kosher and non kosher kitchens silmutaneously. As written by Rabbi Zvi Goldberg, Star-K Kashrus Administrator in his article "Don't Miss the Boat:Halachic Guidelines of Kosher Cruises"

Providing kosher supervision on a cruise ship is not an easy task. "Mega-ships" carrying over 4,000 guests serve more than 12,000 meals per day! Food preparation occurs around-the-clock in multiple locations. Often a 'kosher cruise' means that an entrepreneur has booked a number of cabins aboard a large ship. In such an arrangement, kosher and non-kosher food will be prepared and served simultaneously.

The traveler must have confidence in the kashrus agency. In order to instill confidence, a reliable kashrus organization must address many issues.

Available by: Eddie's Travel (www.koshertravelers.com), Kosherica, SuiteLife - all of whom travel on various large luxury ships such as Costa, MSC, Celebrity.

So which ever way you choose, in the 22nd century jews can travel the world in style and well fed!