Are Cruises Eco-Friendly?

I try to be as eco-conscious about my decisions as much as possible.... when offered to go on a 9-day cruise in the Caribbean, I hesitantly accepted, wondering about the ramifications of that kind of travel on the environment.

We stayed on Royal Caribbean's Explorer of the Seas boat. The huge boat is 9 years old, weights 137 tons, is 1,000 feet long, and 137 feet wide. It holds 3,840 guests, and 1,214 workers. The boat cruises at an average of 25 mph. The boat sails constantly with new groups of guests constantly, all year long. Imagine a moving city/hotel that holds 5,000 people every week of the year = 270,000 people x 9 years = 2,430,000 million people.

Boy, was I pleasantly surprised. I realize now that huge cruise ships must find ways to reduce their amount of trash because it saves them money, hence, making the cruise more eco-conscious for all of us, perhaps more than airlines and hotels.

My bed sheets were never taken out/washed the entire 9-day stay. My used towels, left on the racks, were simply re-folded and put back on the rack (I know because I put a tiny make-up smudge on one corner on purpose).

Here is a photo-journal of all the good eco-things (and some bad) about the cruise I went on.

The showerhead was low-flow, and the warmest setting for the shower was mildly warm. I couldn't increase it to a hot temperature (I love hot showers, so this was a nice way to detract me from taking hot showers!). I also know the ship can provide hot temperatures because in the spa, I used their shower, and it was hot! Wonder why.
This shampoo/conditioner dispenser was excellent, much better than the tiny bottles they put in your hotel room every day. I used this everyday.

Those signs were in every room, every bathroom and peppered on various locations on the ship.

I could control the temperature in my room. Of course we put it at the lowest possible setting, but the air conditioning in the cruise liner was too strong (yes I froze), and the cold air still seeped in our room regardless of that setting. I was told that people remedy this by opening their balcony window to let the outside air in (which is obviously just making the air conditioner run even more). I think this is probably the biggest pet peeve I have about cruises - their freezing temperatures!!!! Royal Caribbean, take note!
Their trash cans in the rooms are NOT lined with plastic bags.
The bathroom trash can, again, NOT lined with a plastic bag. Nice! When I had my period (yes I got it on the cruise, ugh), there were paper bags specifically for discarding pads and tampons that said "100% recyclable" and "biodegradable". Hmm. Too bad, I forgot to bring my Sea Sponges!!! So I bought tampons from the cruise shop - double UGH).

I didn't take a picture of my laundry bag (they washed my clothes) and returned it in a paper bag (not plastic). The original laundry bag was plastic, though....

All of their lights are LED bulbs that put out less heat and require significantly less energy.
Recycling bins can be found on each floor.
Unfortunately, their milk comes in paper cartons (better than plastic, regardless). I also was disappointed the condiments were all individual sized (ketchup, mustard, relish, syrup, butter, and so on). There should be bulk canisters for these things. Also, water is provided in dispensing tanks, so there were no plastic bottles anywhere. You could purchase them from the ship, but of course they were tad too expensive (thank goodness), and I didn't see anyone drinking from them or leaving them around.
All of the utensils, dishes and napkins were metal, plastic/ceramic or cloth. I only found one small section of the ship that provided paper napkins (and it was hard to find).

A small half-page article in a thick magazine by the Royal Caribbean cruise for the 2009-2010 year mentions their endeavors in being eco-conscious. They mention that all their windows have tinging materials that filter out almost all UV rays which saves air conditioning (if only they'd turn down their air conditioning setting!). Their dishwashers, laundry equipment, ice makers are all water-conserving and energy efficient. The newer ships all have better hull shapes and improved propeller systems which save energy and fuel.

What do you think? Do those little things cancel out the amount of carbon emissions the ship emits? I wish I took a photo of the gray-black billowing smoke from the top of the ship. Does the moving ship make a negative, irreparable impact on the ecosystems underneath?

(not a photo of a Royal Carribean ship, it's a photo I found on the internet)

I've read that it's better to cruise than to fly, because of the low MPH (the lower MPH you go, the more fuel you save over time) and I've never met a plane that could carry 5,000 passengers, board them, feed them, and take them to 4 islands over 9 days. What do you think?

p.s. This blogging style, "photo-journals" - I borrowed from Beth Terry, blogger at Fake Plastic Fish. I love her blog posts, check her out!