ST. PETERSBURG -- The Tampa Bay Rays, who have played indoors at Tropicana Field for their first 10 seasons,unveiled plans on Wednesday for a retractable-roof, 34,000-seat, open-air waterfront ballpark that could open as early as 2012.

The Rays pledged that the $450 million facility, to be located on the site of the historic Al Lang Field Spring Training facility, will require no new taxes or the reallocation of existing taxes, though the complex financing plan must first clear several hurdles, including the transformation of the 85-acre Tropicana Field site into a retail and residential district.

"This is not going to be an easy production," said Rays principal owner Stuart Sternberg. "Things that have value in life rarely are easy. They come from hard work and determination. ... The Rays recognize the hard work that is ahead of us."

In a news conference held in the outfield of Al Lang Field, team officials, Florida governor Charlie Crist, and MLB president and chief operating officer Bob DuPuy praised the design of the state-of-the-art ballpark, which will include a unique retractable roof made of a weatherproof fabric that will be pulled along cables suspended between arches on one end and a central mast structure on the other.

"This is one of the most exciting things I've ever seen," said Crist, who owns a condominium that will have an unobstructed view of the outfield.

Just two days before December, Crist and the other officials sweated in suits and ties on a dais located just a relay throw from the Mahaffey Theater, site of Wednesday night's CNN/YouTube debate among Republican presidential hopefuls. It was a reminder of how sultry conditions could be during late-summer games.

The roof, likened to a giant sail, will produce an umbrella effect, retaining the open-air feel. Rays officials, working with HOK Sport architects, deemed a traditional retractable roof impractical because of the small site and undesirable, since it would block the water views.

The design calls for climate-cooling techniques that will lower temperatures 8-10 degrees. Those include keeping the "sail" up during the days before games. Michael Kalt, the Rays senior vice president of development and business affairs, said the process should at least make the mid-summer temperature inside the stadium comparable to those in Baltimore, Kansas City, and St. Louis.

Tropicana Field, which opened in 1990 as a multipurpose stadium built to attract Major League Baseball, was the last ballpark constructed before Baltimore's Camden Yards inspired a new era of ballpark innovation. Though "The Trop" has undergone several renovations, most recently in 2006 under Sternberg's two-year-old tenure as principal owner, it lacks the amenities of newer facilities.

Like San Francisco's AT&T Park, the proposed facility will be configured so that home runs traveling over the right-field wall could land in the water. During the news conference, Rays first baseman Carlos Pena stood in right field at the approximate point of where home plate will be in the new ballpark. He swung at several pitches thrown by Rays coach Tom Foley, eventually hitting one into Tampa Bay.

The ballpark will feature the smallest upper deck in baseball, and a new public park that will link the waterfront park system to the north of the ballpark with the emerging cultural district to its south.

Sternberg said the Rays will contribute $150 million toward ballpark financing. A large part of the financing is the redevelopment of the Tropicana Field site into a major retail, entertainment and housing development.

The Rays have partnered with Hines, a leading developer of mixed-use projects, to develop a site plan for the Tropicana Field redevelopment. Hines will compete for the rights to develop the site through a Request for Proposal (RFP) process managed by the city. The city council also must approve adding to the November 2008 ballot a referendum to authorize construction of the new ballpark on the Al Lang Field site, and voters must approve the measure.

If the referendum passes, construction on both sites is anticipated to begin in mid-2009, with the new ballpark ready by Opening Day 2012. The Tropicana Field development is scheduled to open in 2011 and continue through approximately 2013.

Playing host to the Major League Baseball All-Star Game conceivably wouldn't be far behind.

"The commissioner has made it a practice of showcasing -- this year is an exception because we're celebrating the history of Yankee Stadium -- new ballparks," DuPuy said. "There haven't been as many in the American League as in the National League. A new American League ballpark would be very helpful."

City officials had hoped that Tropicana Field, built in 1990 as a multipurpose stadium, would spark development in the surrounding area. But while the downtown waterfront area has flourished since the Rays began play in 1998, with million-dollar condominiums now common, little has changed in the area one-mile away near Tropicana Field.

"With a sea of parking lots around Tropicana Field, it's hard to build that momentum in the surrounding areas," said Rays president Matt Silverman. "With these two new projects, we're confident we can bring that development to the area where it was originally intended."