A new fleet of cruise ships hits the water this year, the likes of which have never been seen. When Royal Caribbean's Freedom of the Seas launches in June, it will surpass the Queen Mary 2 as the world's largest passenger ship. A month later, the Costa Concordia will jump to the top of the list in terms of capacity, with 3,780 passengers. But it's not just the size that's impressive. The new boats are loaded to the gills with diversions: Freedom of the Seas has an ice rink, a wave pool, and a regulation-size boxing ring.

COSTA CRUISES: COSTA CONCORDIA

Costa Cruises (courtesy Costa Concordia) [enlarge photo]

Launch date: July

Passengers: 3,780

Itineraries: 7-, 9-, or 11-night cruises out of Rome with stops in Istanbul, Venice, Barcelona, Alexandria, and Santorini Cool

Features: Samsara, a two-level, 20,000-square-foot spa--the largest at sea--with a thalassotherapy pool, in which seawater is used for body wraps. Less relaxing, but more fun: the Formula 1 racing simulator (price to be determined)

Something Special: Retractable roofs over the pools on the top deck for when the weather turns chilly

Splurge: As on most ships, the best restaurants aren't included in the cabin price. Options include Ristorante Samsara, for lighter fare near the spa (from $23), and fine Italian dining at Club Concordia ($29)

ROYAL CARIBBEAN: FREEDOM OF THE SEAS

Launch date: June

Passengers: 3,634

Itineraries: Seven-night round trips from Miami, with stops in Cozumel, Grand Cayman, Jamaica, and a private beach in Haiti