Early in the morning in Valletta, Malta, a crew member swabs the deck of the Celebrity Silhouette, a year-old state-of-the-art cruise ship.
Early in the morning in Valletta, Malta, a crew member swabs the deck of the Celebrity Silhouette, a year-old state-of-the-art cruise ship. (Karen K. Hansen )

As we neared the end of a Mediterranean and Adriatic cruise, the ship's captain shared some statistics that captured the enormity of operating a modern cruise ship.

"Since leaving Venice 12 days ago," he said, "we have visited five countries, stopped in 10 ports, served 120,000 meals and burned 1,000 tons of fuel."

Although the captain didn't mention it, the 15-deck craft that had housed, fed, entertained and transported 2,999 passengers and 1,223 crew members also had generated thousands of gallons of black and gray water and tons of solid waste.

That doesn't necessarily mean a cruise is the Hummer of all vacations. It's a relative matter, not an absolute one. Flying to Disney World and renting a car or driving roundtrip from St. Paul to the Black Hills with hotel and restaurant stops along the way certainly have environmental costs.

When Conde Nast Traveler polled readers recently, 93 percent of those responding thought travel companies should be responsible for protecting the environment.

We are a husband-and-wife team who work as cruise ship lecturers two or three times a year. We wondered about the environmental impact of our working vacations. Short of conducting a worldwide environmental impact study ourselves, we hoped that acquiring some inside information would tell us what at least one cruise line is doing to minimize its ships' environmental wakes.

We contacted Celebrity Cruises (a division of Royal Caribbean International, the world's second-largest cruise ship company) and made arrangements to interview the relevant crew and observe the latest environmental technology and programs in action for this article. We were booked on the Celebrity Silhouette, the line's year-old state-of-the-art ship, sailing from Venice to Rome with port stops in Croatia, Italy, Malta, Montenegro, Sicily, and Slovenia in July 2012.


As we boarded and explored the ship, it was impossible to miss the "Save the Waves" plaques that line the rails on all decks and the big blue recycling bins throughout public areas. Staff Captain Alex Papadopoulos, the ship's second-in-command, reports that American passengers are the most compliant about sorting their recyclables into those bins.

Still, we wondered at the absence of separate recycling containers in our stateroom. Finding only one small garbage receptacle in the bathroom and another next to the desk, we set aside our empty water bottles so they wouldn't wind up in the trash.

Screens and pumps filter plastics and other coarse particles out of waste water as a first step in the treatment process on the ship.
Screens and pumps filter plastics and other coarse particles out of waste water as a first step in the treatment process on the ship. (Karen K. Hansen )

Turns out everything goes in the trash, and the crew manually sorts all those bins' contents into their recycling categories. No bottle goes unexamined. The shampoo, conditioner, soap and lotion provided in our room were plenty luxurious and, even better, phosphate-free. When passengers leave bottles and tubes of their own products behind, the crew empty and segregate the contents to keep phosphates out of the ship's water systems and ultimately the sea.

It's all-hands-on-deck for environmental training. From shop staff and stateroom stewards to cooks and captains, all crew members receive training each time they come on board for a new contract, regardless of their tenure.

The consequences for taking environmental stewardship seriously are carrot-and-stick. Sort the recyclables and earn money that goes into a fund for the crew. Flick one cigarette ash overboard and you're instantly unemployed.

Crew members who spot passengers throwing things overboard or otherwise violating ship's policies report the offenders to Papadopoulos, who first issues a verbal warning during a stern meeting in his office. Upon a second offense, the passenger gets an early, no-expenses-paid trip home.


Environmetal officer Thomas Vatianos, with third engineer Nikolaos Stouraitis, raises a glass of cleaned water to toast the ship&#8217;s multistage
Environmetal officer Thomas Vatianos, with third engineer Nikolaos Stouraitis, raises a glass of cleaned water to toast the ship's multistage water-treatment technology. (Karen K. Hansen )

Of all the environmental challenges officers and crew face, the toughest are those involving chemicals. The ship's environmental officer, Thomas Vatianos, explained that the company continuously tests and adopts new cleaning supplies with ever-decreasing levels of toxicity. That results in less toxic work for cleaning crews and fewer chemicals lingering on surfaces and washing into the ocean.

There's also the passengers: Cruise ship passengers are intensive water users. Once upon a time, all that waste water from the kitchen, laundry, bathroom sinks and even the toilets simply was flushed into the ocean.

Those times are over. Modern ships have wastewater treatment systems that remove the bad stuff and discharge cleaned water under stringent international standards known as MARPOL (International Convention for the Prevention of Pollution from Ships).

Below the waterline on decks 1 and 2 of the Celebrity Silhouette are the enormous power plant that propels the ship, gigantic fuel storage tanks, miles of pipe that make up the water-treatment system and the other environmental systems that support -- and clean up after -- life on the passenger decks above.

Down there, there are no waiters serving cocktails, no dance lessons and no spas. The nether reaches of a cruise ship, where environmental officers and engineers work, are hot, noisy and spotlessly clean.

The Celebrity Silhouette's immense advanced wastewater treatment system uses a combination of waste-eating bacteria, screens, filters and ultraviolet light to turn black and gray water into near-potable water before it is discharged into the ocean. In a small but very high-tech lab, Vationos and his team test the discharge-bound water daily.


Perhaps the most egregious environmental problem on the oceans is the poor quality of the fuel burned at sea. Called bunker fuel, the stuff burned in seaborne diesel engines is notorious for its high sulfur content, which spews out of the smokestacks in the form of sulfur dioxide, a notorious pollutant.

There is good news on the horizon: By 2015, every cruise ship that comes within 200 miles of the United States -- the vast majority of ships -- must burn diesel fuel that is nearly free of sulfur. According to Vatianos, his ship is ahead of the game, already burning the cleaner fuel.

Food for the cruise arrived by truck from all over Europe, with one restock in Bari, Italy, halfway through the itinerary. Some of what went to waste, rather than to passengers' waists, was incinerated, including meat bones, while the softer stuff was macerated on board.

Under MARPOL regulations, the resulting mash can be released into the water after a ship is 12 miles out to sea. It's considered food for marine life, and when a ship travels at a speed of 6 knots or faster, the dissolution of the food in the water is deemed to be complete. The fact that it's not a normal part of the food chain gives us pause.

Also on the Celebrity Silhouette, solar energy use was incorporated in the design phase. Solar panels above the enclosed swimming pool power 7,000 lights on board. That's a fraction of the total lighting load, but Vatianos takes the success to date as an indicator of prospects for greater solar-generated power onboard.

Vatianos himself and his position are signs of the times. He has a university degree in environmental science rather than a diploma from a merchant marine academy, like most other officers aboard. In addition to holding officer rank and reporting directly to the captain, Vatianos reports independently to corporate headquarters, which gives him authority to blow the whistle on anyone on the ship, including the captain, who he believes is violating company environmental standards.


According to International Energy Agency statistics, each American, on average, annually consumes the equivalent of about 7,000 kilograms of oil energy, through heating and cooling their homes, driving, cooking, laundering and performing other daily activities. In the United States, each of us -- again, on average -- uses about five times more energy than a person in Mexico, twice as much as a typical Italian, about 20 percent more than a Norwegian and on par with a Canadian. On the brighter side, an American uses less than half as much as a Qatari or Icelander.

During our 12 days onboard the Celebrity Silhouette, the yearly equivalent energy usage was 6,100 annual kilograms of oil per person. This was calculated by determining the energy content of the fuel used, multiplying that by the amount consumed and then dividing that figure by the number of people onboard.

For this cruise, at least, life at sea was the energy-use equivalent of spending the time as a Norwegian instead of an American. Our particular trip's usage may have been a bit lower than other itineraries, as ours was confined to the eastern Mediterranean and Adriatic seas and covered relatively few miles between ports. While for us this itinerary required a plane trip to Europe, most people onboard were European.



Cruise lines compete hard for passengers' business, and it's fair play to choose your vacation based on their environmental records as well as what suits your travel dreams and budget. You can start by surfing their web sites and those of environmental and travel organizations that track their records.

Here are additional factors to consider:

-- Choose a route that traverses fewer miles and has more days in port than at sea. The more port days, the less fuel consumed (shore excursions not- withstanding). Such options include Caribbean, Mediterranean, Adriatic and Baltic routes. Cruising from Mumbai to Dubai with a stop in Oman or taking a world cruise? Less green.

-- Big ships are more energy-efficient than smaller ships. Although air conditioning, water heating, and electricity generation consume energy, these pale in comparison with moving a ship's enormous hull through the water. So, although large ships use more energy overall, on a per-person basis they use less than small ships.

-- New ships are more environmentally friendly than older ships, thanks in part to newer engines that are more energy-efficient. Plus, newer ships pass through the water more easily by combining dynamic trim systems that reduce friction, more efficient power plants and new slick coatings on hulls.

-- Flying to an embarkation port consumes a lot of energy, making cruises that leave from ports closer to home greener than more distant ones.

-- Look for vessels with a record of taking care of the environment. All cruise ships are supposed to comply with MARPOL and the often more stringent regulations and laws of individual countries and states, but some work hard to exceed those standards.

-- Finally, don't leave home without minimizing your in-absentia footprint. Turn down the water heater and turn off the air conditioner or dial the furnace temperature down. Then go have a grand time on the high seas, understanding that there is no completely green way to travel ... or to stay home.