Cruise lines are in a heated race to build larger and more lavish cruise ships. Royal Caribbean's "Wonder of the Seas," currently the world's largest cruise ship, has a staggering 18 decks and a capacity of nearly 6,988 passengers plus 2,300 crew members. That's roughly the equivalent of the population of Sedona, Arizona. These ships take years to build, and feature everything from ziplines to artificial surf machines, and actual neighborhoods full of restaurants, bars and stores to entertain passengers at sea.

But bigger and bigger is not always better, especially when these floating cities visit smaller ports that are unable to accommodate the vessels or the sudden influx of people getting on or off the ships.