Don’t pack your bags for Havana just yet.

Fidel Castro may have announced his resignation, but that doesn’t mean you’ll be touring the Plaza de la Catedral, strolling along Varadero Beach or diving on Isla de la Juventud any time soon.

“It’s still early for the American tourist to plan on sipping a mojito at the Hotel Nacional,” says David Guggenheim, who directs the Cuba program at the Harte Research Institute for Gulf of Mexico Studies at Texas A&M University in Corpus Christi, Texas. “But change just might be in the wind.”

It could take time — months, or even years — before Cuba becomes the hot destination it used to be for American visitors, according to experts. But the doors to this once-closed island nation are already open to some Americans, and Castro’s retirement is likely to open them even wider.

Nothing is likely to change while President Bush remains in office. However, after the presidential election in November, and just in time for tourist season in the Caribbean, people expect a thaw. “Raúl Castro has indicated in the past that he would be open to a dialogue with the U.S., and presidential candidate Barack Obama has expressed his willingness to open a dialogue with Cuba,” says Guggenheim.

Not quite closed
Travel to Cuba isn’t illegal for Americans — at least, not all of them. Government officials, journalists, researchers and people attending conferences are allowed to visit the island nation, according to the State Department. Technically, travel to Cuba is limited under the Cuban Assets Control Regulations and the Trading With the Enemy Act.

About 65,000 Americans visited Cuba legally in 2006. Among them were students at Ohio Northern University’s 11-week program in Environmental Management at the University of Havana. Terry Maris, an Ohio Northern University management professor who has visited Cuba many times as an academic, estimates that approximately 150,000 American tourists visit Cuba each year illegally. “If the embargo were to be lifted by the U.S. government, it is estimated that from 3 to 5 million American tourists would visit the island in the first year alone,” he says.

And that’s just the start. Several years after travel restrictions are loosened, Havana could conceivably become a subtropical Las Vegas — which is more or less what it was before Castro came to power.

“In the post-World War II period, Cuba outranked all countries in the world in the volume of passenger flow to and from the United States,” says Lisandro Pérez, a sociology professor and Cuba expert at Florida International University in Miami. “With jet airplanes, the actual flight is less than half and hour. Havana and Varadero are closer to Miami than Disney World.”

So what if there’s an embargo?
Once you have a license to visit, you can fly directly to Cuba from Miami, New York and Los Angeles on charter flights operated by some of the major U.S. airlines. But there are other ways to reach Havana. Some of the most popular routes include stopovers in Mexico, Canada, the Cayman Islands, Jamaica and the Bahamas. (A helpful site for planning a Cuba vacation is the Cuba Tourist Board’s Canadian Web site.

Among the options:

– For larger groups, Miami-based ABC Charters offers flights to licensed groups visiting Cuba.

Signature Travel, one of the largest tour operators in Canada, has all-inclusive “dollar stretching” Cuban packages to Varadero, Cayo Coco, Holguin, Cayo Largo and Havana.

– Fort Lauderdale, Fla.-based Tico Travel runs tours to Cuba for licensed U.S. travelers, but it is also a good resource for visitors who would prefer to go the legal route.

Sure, getting to the island can be something of a hassle. But experts don’t think it will stay that way for much longer. “There’s momentum in Congress to make travel to Cuba easier,” says Susan Eckstein, a sociology professor at Boston University. “As U.S. business interests in Cuba pick up, there is support for lifting travel restrictions.”

But for most Americans, it may be a good idea to sit tight until the embargo is lifted. Not just for practical reasons, but also because it’s the right thing to do, says Thor Halvorssen, president of the New York-based Human Rights Foundation. Even with Castro gone, Cuba remains a totalitarian police state, according to the State Department. Halvorssen likens conditions in present-day Cuba to Apartheid South Africa, at least when comparing the plight of ordinary Cubans with tourists.

“Local people are not allowed to enter the hotels where tourists can stay,” he says. “Tourists eat like kings at the hotel buffet which Cubans — even if they have the cash — are not allowed to use.”

Americans, he adds, “should avoid the hypocrisy of visiting that kind of country.”

What’s next?
When I lived in South Florida, I met many Cuban immigrants who longed for the day Castro was gone and they could return home. For me, there was no better symbol of that desire than the Southernmost Point buoy in Key West, which announced Havana was only 90 miles away. In the near term, at least, Havana might as well be on another planet, say people who are familiar with the situation.

“As far as legal travel, nothing has changed,” says Maria Lopez, host of the TV show “Judge Maria Lopez” and a Cuban immigrant who has visited Cuba more than 30 times in the last decade. “Hopefully Fidel Castro’s departure will help change U.S. policy to allow unrestricted travel to the island.”

Part of the problem, say people who have seen Cuba recently, is that its tourism infrastructure would buckle under the weight of all the American tourists. That’s one good reason to wait.

“Cuba only opened to tourism in the early 1990s, in response to the collapse of the Soviet Union,” says Jack Kenny, author of the book “Cuba” (Corazon Press, 2005). The hotels built back then, he adds, were only meant to support a few million visitors from Europe and Canada. But the prospects of more Americans coming should spawn more investment in hotels and tourist attractions, which could ultimately support throngs of tourists from the mainland.

Until then, travelers who want to experience Cuba might want to book a ticket to Miami. At least that’s the view of William Talbert, president of the Greater Miami Convention and Visitors Bureau. “It will take some time before Cuba can put in place the same infrastructure that Miami has,” he says. “Besides, we have the Latin flavor here.”