All cruise lines have upgraded the ships they use for weekend cruises from South Florida. Among the improvements:CARNIVAL
Carnival recently refitted the Carnival Imagination, which sails from Miami, spending $31-plus million to revamp staterooms, refresh the spa, refashion the teen club and redesign the pool decks with a four-story water park separate from the main pool area and a separate adults-only ''serenity'' outdoor space. (All eight of its Fantasy Class ships, built in 1990s, will receive the upgrades in coming months.)
In September, Carnival will add even more short-cruise cabins, bringing in the 101,000-ton Carnival Destiny, which carries 3,360 passengers, to replace the 70,000-ton Imagination on short sailings from South Florida.CELEBRITY CRUISES
Celebrity Cruises poured $55 million into its 1,800-passenger Century in late 2006, adding a sleek martini bar, revamped spa, teen club and balconies to many cabins.DISCOVERY CRUISE LINE
In 2002, Discovery invested $1.3 million, adding a childrens' club, new casino and lounge, and upgrading carpets and some cabins and public spaces.IMPERIAL MAJESTY
The line upgraded it's ship in January 2008, adding a spa and children's area and changing out carpet. The company declined to name the dollar value of its upgrade.ROYAL CARIBBEAN
Royal Caribbean spent $60 million in 2005 to literally stretch its Enchantment of Seas, which sails from Fort Lauderdale, cutting the ship in half and inserting a 73-foot-long span that enabled the line to add 151 cabins, a steakhouse and a Latin-themed dance club, and lengthen the pool deck.
In 2007 it upgraded Majesty of the Seas, adding specialty restaurants including Johnny Rockets, Sorrento's pizza and coffee and ice cream shops, and a Latin-themed Boleros nightclub.
This past winter, it also brought in one of its megaships -- 142,000-ton, 3,835-passenger Navigator of the Seas, with ice-skating rink, nine-hole mini golf course, rock-climbing wall and golf simulator, built in 2002 -- for six months of short cruises from Fort Lauderdale; the trips were so successful that the ship will stage an encore next year.NCL
In July, NCL brings the Norwegian Sky -- formerly the Pride of Aloha -- to Miami. Purpose-built for ''freestyle cruising,'' which features multiple restaurants, the ship was launched in 1999. NCL will spend $15 million-plus to add a casino and upgrade cabins before the ship re-enters service.
-- JANE WOOLDRIDGE