In some instances, only the cruise-only fare is available. That's a term that refers to anything you do off the ship, in port. At every stop, you'll have the option of exploring the area on your own or as part of a group with a planned itinerary. You might hike a tropical rain forest in the Caribbean, fish for king salmon in Alaska, tour Mayan ruins in the Yucatan Peninsula of Mexico, or take a sightseeing tour. They range from yacht-like vessels with 100 passengers to towering megaships with huge atriums and a maximum capacity of nearly 3,000 people.
All cruises now require proof of citizenship.
On some itineraries, a certified copy of your birth certificate and a driver's license or government-issued photo I.D. are sufficient, on others a passport is required. Visas may also be required on the more exotic itineraries. Your cruise counselor will advise you on documents you will need depending on your itinerary. Children of all ages are welcome on most ships. Your cruise counselor can advise you of the dwindling number of ships that are not kid-friendly.