????By Jeffrey M. O'Brien

????Royal Caribbean Cruises hopes enviro-friendly Oasis of the Seas can burnish its green image.

????The world's largest cruise ship — featuring 16 decks and an interior Central Park that's longer than a football field with more than 12,000 species of flora — is drawing ever closer to its home port of Port Everglades, Florida, where it will dock next week and conduct a few test runs before departing on its maiden voyage early next month in Caribbean waters.

????Two years and $1.4 billion in the making, Royal Caribbean's new baby is a true colossus — almost a quarter-mile in length, bigger in every direction than any passenger ship that has ever sailed and 40% larger than the company's next biggest ship. Capable of carrying 5,400 guests in 2,700 rooms and more than 2,000 crew members, it boasts almost five times the gross domestic tonnage of the Titanic.

????Manufactured by STX Europe in Turku, Finland, the Oasis represents a technological feat on many levels. It can travel up to 10 knots moving sideways, for example, and has retractable smokestacks and a pool with a movable floor. But Jamie Sweeting, Royal Carribean's chief environmental officer, is most proud of the ship's green cred.

????Reduce, reuse, recycle

????Notorious for consuming massive amounts of fuel, dumping waste into the oceans and spewing carbon into the skies, cruise ships have abysmal environmental track records. Miami-based Royal Caribbean (RCL) has at least been talking about environmental stewardship since the early '90s, when it developed its so-called Save the Waves program, which basically amounted to a nice catch phrase: reduce, reuse, recycle.

????"That has now turned into an operating philosophy," says Sweeting, noting that Oasis of the Seas is the first cruise ship to receive a Green Passport. The ship "is really a culmination of everything we've learned to date. The carbon footprint per passenger is 40% less than ships built just ten years ago."

????Oasis uses a combination of sophisticated technology and design sense to achieve that savings. Several hundred interior rooms face Central Park, for example, to make use of natural light and lessen energy requirements. Rather than propellers, the ship uses azipods, which can rotate 360 degrees and pull the ship through the water at speeds of up to 25 knots. Pulling nets a 10%-15% energy savings compared to propellers.

????"We produce electricity on board and use that electricity to drive the propulsion," says Sweeting. "The best way to deal with air emissions is to not have them in the first place." The ship also uses LED lights and Energy Star appliances to reduce load, recaptures heat off the engines and incinerators, and treats wastewater to the point where "it meets or exceeds municipal watewater treatment plants," he says. "It's basically the quality of bottled water when it comes out."

????Green holidays

????Sweeting says all this effort isn't exactly at the request of customers. Generally, people don't want to think about being green when they're on vacation. Which is why he has to do it for them. And of course he and his superiors are hoping that the "green" aspect of the Oasis will be a selling point at a time when all non-essential travel, including the cruise business, is hurting.

????It better be, because Oasis's identical sister ship — Allure of the Seas — will be arriving a year from now, and it's too late to cancel the order.