<p id="story-body" style="clear: left">When it comes to cleverly using the limited but ever-expanding real estate on cruise ships, maritime designers have often stepped outside the box. <br /><br />Royal Caribbean International, for one, introduced numerous innovations that took seafarers by surprise&mdash;rock-climbing walls, ice-skating rinks and wave surfing, to mention a few. <br /><br />Norwegian Cruise Line, too, is no slouch in pushing the envelope. Some of its vessels debuted with sequestered Courtyard Villas for top-paying passengers and a funky nightclub that combines a bowling alley with a disco area that hearkens to a Turkish harem. </p><h2 class="subhead">New wave in staterooms</h2><p>In the latest oceangoing battle to distinguish one ship from another, NCL's architects are pushing boundaries further. </p><p id="story-body2">For the next generation of staterooms on two 150,000-ton, 4,200-passenger vessels to be delivered beginning in 2010, NCL will throw passengers a curve, at least architecturally. On its F3-class vessels, New Wave staterooms, as NCL dubs them, will have wave-shaped walls separating cabins. <br /><br />The design maximizes the living space and allows for a bathroom that is completely unique, according to NCL's announcement. It will have a separate shower stall, separate water closet and a modern vanity-top sink. <br /><br />Perhaps the most unusual use of real estate on NCL will take the form of a Nordic ice bar, essentially a &quot;frozen vault full of iced vodka,&quot; noted NCL CEO Colin Veitch. The bar as well as the stools and tables, glasses and accessories will be crafted from ice. Inspired by Scandinavia's ice bars and ice hotels, NCL's bar, dubbed Cool, will be so cool (17 degrees Fahrenheit) that passengers will be given fur coats, gloves and hats to stay warm. (For details, visit www.ncl.com.)</p><h2 class="subhead">Away from it all</h2><p>Two years ago, Princess Cruises broke the mold when it introduced The Sanctuary, an adults-only retreat far from the hubbub of the pool deck on the Emerald Princess. The secluded spot provides passengers with an exquisite private getaway within a plush, outdoor spa-inspired setting. The seagoing oasis boasts two private massage cabanas, designer chaise longues tucked amid palm trees and Tivoli lights that add sparkle. Especially attentive service and amenities will be offered, including chilled face towels, Evian water atomizers and MP3 players with noise-canceling headphones. <br /><br />The concept has been so appealing to passengers that Princess will replicate the Sanctuary fleetwide, starting with Ruby Princess in November ( www.princess.com). </p><h2 class="subhead">Holland America's Eden</h2><p>Holland America Line will debut its own version of an Eden at sea when it launches the 2,104-passenger Eurodam this summer in Rotterdam, the Netherlands. Bedecked with 14 airy, tented cabanas, Holland's private spa-like Retreat occupies two decks&mdash;the Observation Deck and the midship pool area on Lido Deck. The decor includes contemporary woven chaises, ottomans and upholstered settees. Each cabana comes stocked with bathrobes and plush towels, handheld fans, an Evian spray mister and preloaded iPods. Gastronomic pampering in the Retreat includes iced fruit skewers in midmorning and frozen grapes, chocolate-covered strawberries and a glass of champagne in the afternoon ( www.hollandamerica.com). </p><h2 class="subhead">Celebrity's Lawn Club</h2><p>Debuting in December, the first of Celebrity's new Solstice-class ships, carrying as many as 2,100 passengers, will feature the Lawn Club, a half-acre area on the ship's top deck that will boast a lawn of living grass. There, passengers can play bocce ball and croquet, picnic with wine and cheese, practice their golf putting or, as the line notes, &quot;enjoy the sensation of grass beneath their feet while they're miles out at sea.&quot;</p><p>Things will get even hotter on Solstice with the ship's Hot Glass Show. In collaboration with New York's Corning Museum of Glass, the vessel will house its own dedicated glass-blowing studio. The show will present the history and craft of glass-blowing as well as entertain passengers with live glass-making demonstrations (www.celebrity<br /><br />cruises.com). </p><h2 class="subhead">City on the sea</h2><p>Meanwhile, Royal Caribbean merits a nod for yet another bold design. When the line lofts its flag on the world's largest cruise ship in 2009, Oasis of the Seas, it will debut a lush tropical park the size of a football field at its core, with surrounding neighborhoods and a panoply of restaurants. <br /><br />For those familiar with the line's Voyager-class ships, the Central Park concept sounds a bit like the Grand Promenade, only alfresco. It will feature serene pathways, seasonal flower gardens and a canopy of trees that eventually will soar 21/2 decks high. Several hundred staterooms, half of them balcony aeries soaring six decks above the open space, will be rooms with a view of the park. </p><p>Royal Caribbean's city-at-sea concept also includes a Coney-Island-like Boardwalk, an AquaTheater offering evening water shows, a carousel, two rock-climbing walls and the first zip-line at sea, suspended nine decks above the Boardwalk. Designed to resemble nostalgic seaside piers of the past, the Boardwalk is awash with eateries, carnival games and retail outlets, including a tattoo parlor offering temporary appliques </p>