You can't describe Royal Caribbean's new flagship without splashing on the superlatives. The Oasis of the Seas is the longest (1,187 feet), tallest (240 feet), widest (208 feet), heaviest (225,000 gross registered tons), and most expen-sive ($1.4 billion) passenger ship ever launched. As its 6,296 guests (that's 40% more than the next biggest boat) cruise the Caribbean, they can entertain themselves with a glut of floating firsts, from the outdoor, tree-lined park to a cocktail bar in an elevator to performances of Hairspray in the 1,350-seat theater. The only thing this pleasure ark lacks? Animals, two of each. -- THEUNIS BATES