SeaWorld Orlando is preparing to build a roller coaster billed as the theme park's most ambitious and expensive attraction yet.

It will be part thrill ride and part animal attraction, a theme that visitors will experience from the time they take their place in line until the time they leave the post-ride area, said Joseph Couceiro, vice president of sales and marketing for SeaWorld's parent company, Busch Entertainment Corp.

"It's going to have animal components, marine-life components. It will have a very unique, state-of-the-art ride, a roller coaster if you will, that will provide a sensation of gliding," Couceiro said. "The combination of the animals and the ride is what makes it special."

Couceiro and other company executives unveiled the project Wednesday evening to a gathering of travel-industry and community VIPs at SeaWorld for the kickoff gala of two other new attractions: Aquatica in Orlando and Jungala in Busch Gardens Tampa Bay.

The coaster signals a new boom time for development at the region's theme parks, combined with the Aquatica water park, which celebrates its grand opening Friday; the multiple-attraction Jungala area in Busch Gardens, which has its grand opening in Tampa today; several attractions about to open or under way at Universal Orlando; and a new simulator ride at Walt Disney World.

The tourism industry may be generally concerned about the soft economy right now, yet the theme parks are spending hundreds of millions of dollars on projects.

"Not that I'm at liberty to discuss dollars, but this is the largest single investment we've made at any one attraction at any SeaWorld park," Couceiro said. "It's us investing in a destination that we feel very confident about. . . . We want to make sure that we remain as a must-do experience when visitors come to Orlando."

The SeaWorld coaster should have an effect on the marine-life park similar to that envisioned for another big-dollar attraction announced two weeks ago by rival Universal Studios, which is building its Hollywood Rip, Ride, Rockit roller coaster.

Both are designed to become bold new focal points for their respective parks' entrances. And each is to become its park's new anchor attraction.

Couceiro said the new SeaWorld ride would be visually "both appealing and compelling."

Few other details were disclosed Wednesday night -- not even a name. No cost estimate was announced.

The coaster is set to open in 2009.

"What it's going to be is the next-generation SeaWorld attraction," Couceiro said. "What we do well is connect the world with the sea, presenting marine life in totally different perspectives. Also, what we do well is put the guest in the midst of that. This is the next generation of that."

He and other officials were reluctant to call the ride a roller coaster, though they said it would have roller-coaster components. They said the attraction would combine entertainment with marine-life education.

SeaWorld began clearing land for construction this winter.

The ride will go into the area formerly occupied by a flamingo-habitat exhibit, a backyard-habitat exhibit, other small exhibits and a gift shop.

The Aquatica water park, which opened March 1, features a water slide called Dolphin Plunge that passes through a pool with live dolphins by using clear tubes.

That 59-acre park also includes other slides, rides and beaches.

Jungala combines Busch Gardens' animals, including tigers, with new rides and dining experiences.

In addition to announcing its centerpiece roller coaster, Universal Orlando recently opened an attraction called Disaster! and will open The Simpsons Ride (with a reported $30 million price tag) in coming weeks.

Universal also is building a new attractions area called "The Wizarding World of Harry Potter," with a reported price tag of at least $230 million.

Disney World plans to open its $80 million Toy Story Mania! ride in Disney's Hollywood Studios in coming weeks.

SeaWorld officials also announced Wednesday that they will offer more nighttime features this summer to encourage visitors to spend the day at Aquatica and the evening at SeaWorld.

"SeaWorld AfterDark" is billed as a giant nightly rock-'n'-roll party, with music throughout the park, a summertime "Shamu Rocks" show, a new water-ski show and other activities.

The water-ski show -- the first offered at SeaWorld in two years -- will feature giant kites, live music and a beach concert.