The newest ship in the Oceania fleet isn't actually new — the 684-passenger ship was built in 1999, and most recently sailed as the Ocean Princess. Fresh from a $50 million upgrade, the ship has more than just a new name. Sirena is classy, intimate, and attractively Old World — think floating Ritz-Carlton hotel. Dark woods, faux fireplaces, and plush furnishings make you feel like you're in someone's fancy living room, while colorful art, mostly by Miami-based artists, adds a contemporary edge.