Friends of the Earth, a non-profit environmental advocacy group, just release an environmental report card for the various cruise lines. I once took a cruise vacation, and it is not something I would repeat. Cruise ships ram passengers and crew in like sardines, the vast majority of the staff are underpaid workers picked up in third world countries, and trash is offloaded in ports willing to « treat » it at the lowest possible cost. Of all the cruise ships, the northern european ones ranked highest and Mickey Mouse a.k.a. Disney pulled into port last.
Travelling by boat changes your perspective. On a ship, you realize the imensity of the ocean and your precarious position bobbing along on it. Also, your impact on the environment becomes terribly apparent. On land, your impact is hard to observe as your impact is diffused across houses, offices, and transportation. On a boat, all the trash from all the passengers passes through one pipe, allowing you to see your real impact. When you travel by boat, you really see the quanitity of garbage you produce, water you consume and gasoline you use.
Wall-E, a movie by Pixar, now Disney (how ironic), mocks the cruise ship industry of the future where robots serve humans to the uptmost degree, relieving them of the painful excercise of working, thinking, and even walking.