By Marnie Hunter, CNN

(CNN) -- Thanks to a $250 million transformation, Royal Caribbean's once-sleepy private island retreat in the Bahamas is offering eye-opening travel amenities to its cruise passengers.

The island, Perfect Day at CocoCay, offers everything from a record-setting water slide and a massive wave pool to five new complimentary dining venues and quiet sandy beaches.

"We are so proud to bring our 50-year legacy of innovation ashore to transform an incredible island that now completely revolutionizes private destinations in the vacation industry," said Michael Bayley, Royal Caribbean International's president and CEO, in a statement.

Reviews site Cruise Critic seconds that notion. Colleen McDaniel, the site's editor-in-chief, said the "revolutionary" island is "really upping the cruise line private island game in terms of activities ashore."

At CocoCay's Thrill Waterpark, the fiery red and orange Daredevil's Peak water slide towers over the park's other 12 slides. At 135 feet, it's North America's tallest water slide.

CocoCay is also home to the Caribbean's largest wave pool, a 1,600-foot-long zip line and a helium balloon tethered to the ground that provides guests with a vantage point 450 feet high.

Oasis Lagoon, the Caribbean's largest freshwater pool, has a large swim-up bar and private cabanas.

McDaniel believes Royal Caribbean may create some cruising converts with this private island offering packed with activities.

"Beyond creating incredible experiences for your avid customers, that's where an investment of this magnitude has the potential to really pay off -- to catch the eye of those who might not have ever tried cruising but are intrigued by this exclusive new experience," she said.

There's an added benefit to cruise line private islands, McDaniel said. They help the cruise lines stagger their itineraries and relieve crowds in popular ports.

"The Caribbean is the cruise industry's most popular region, in terms of passengers and ship deployment," she said. "So having private islands to add to itineraries is quite helpful to the lines to help preserve the in-port guest experience and the port's own capacity."

Perfect Day at CocoCay had its grand opening over the weekend. Itineraries that include a stop at the revamped island are listed online.

One area of CocoCay won't be completed until December. When it opens at the end of the year, Coco Beach Club will feature the Bahamas' first overwater cabanas, each with its own slide into the ocean. There will also be a 2,600-foot beachfront infinity pool and a club and deck area.

CocoCay is the first in a planned collection of Royal Caribbean Perfect Day islands. Additional private island locations are expected in the Caribbean, Asia and Australia.

Several other cruise lines have private islands in the Bahamas, among them Disney Cruise Line's Castaway Cay and Holland America's Half Moon Cay.