Gulf Shores, Ala.: Tarballs began washing ashore weeks ago. More recently, oil deposits arrived.  Images of tar balls on beaches and oily sheens looming offshore are spooking tourists this summer, leading many to forgo vacations along the Gulf of Mexico.  While trip-planning is tricky—government forecasters are reluctant to track the oil slick's trajectory more than 72 hours out—it also can turn up some great deals and great surf at the inexpensive beach jaunts that have been a family staple for generations.  Most of the 1,621 mile U.S. Gulf coastline from the Texas-Mexico border to the southwestern tip of Florida remains clear, with little or no impact from the runaway spill that has been spewing oil for the past 73 days. The longer the oil well stays unplugged, though, the more likely the damage will continue to spread.  The oil slick is generally moving north and east along with Gulf currents. Tourists fretful about where oil could wash up next can track its anticipated daily movements on a website set up by the National Oceanic and Atmospheric Administration.  While Texas has been spared thus far and looks to stay that way, travelers interested in Gulf beach destinations east of the Mississippi river may be better off planning last-minute vacations, when they can be more sure where the oil is.  See how tourism in different parts of the Gulf Coast has been affected by the oil spill.  Storms represent another wildcard, amid predictions the summer hurricane season could be one of the busiest on record. Hurricane Alex, the season's first named Gulf storm, made that clear Wednesday when it began pushing oil into parts of Alabama and Louisiana that had not been seriously soiled by the slick in weeks.  Beach resorts that have been hit with oil point out that they're not blanketed with the stuff and say tourists can still venture into the water on most days. Many have set up webcams so out-of-towners can see real-time images of beach conditions online for themselves. They're also slashing prices, waiving cancellation fees, organizing free concerts and trumpeting non-beach activities such as golfing or visiting an alligator farm.  Florida has rolled out a national advertising campaign, with $25 million in financial assistance from BP PLC, the company that operates the oil well where the accident occurred. The ads, directed at 100 markets, highlight that only a few dozen of the state's 825 miles of beaches have been affected by the spill, and most remain far out of harm's way.  "Our biggest problem is a public relations problem, and not an oil problem,'' says Julian MacQueen, a hotelier in Pensacola Beach, Fla. He estimates June revenues at the Hilton hotel and the Hampton Inn hotel he owns are down 20% and 40%, respectively, compared to last year, even though only a smattering of oil has reached the white sand shores there so far.  For areas closer to the heart of the spill such as Louisiana's Grand Isle, the problem goes beyond image. The barrier island's fabled fishing is now off limits due to tainted waters and a "Tiger Dam," a protection system made of giant water-filled tubes meant to keep oil from encroaching inland, now stands between its popular beach and the water.  Whereas Grand Isle sees upwards of 10,000 visitors on a good summer weekend, it has fewer than 100 these days. And "that might be stretching it," says Josie Cheramie, Grand Isle's tourism commissioner.  Alabama resort towns such as Gulf Shores and Orange Beach also have been sullied for weeks. Neighboring stretches along Florida's Panhandle have had oil wash ashore more recently. Mississippi's coast got its first taste of the brown, gooey mess this past weekend.  Still, not everyone along the Gulf coast is gloomy. Pensacola's pain has become Texas's gain as some beach travelers shift their attention to the Lone Star State, which has not been marred by the spill. (Tar balls washed ashore on Texas beaches Wednesday, though the Coast Guard says they probably are not related to the oil spill, but from natural oil leakage common in the area.)  The Wintzell's Oyster House chain, including this Mobile, Ala., location, has stopped offering oysters at half price during happy hour.  The Galveston Island Convention and Visitors Bureau says visits to its Galveston.com website since April are up 71% among Louisiana residents compared to a year ago. Arkansas visits are up 30%, Missouri 22% and Mississippi 78% in what officials see as a sign that tourists are redirecting vacations westward.  "Oil weathering," "nature's seeps," and other factors to monitor when planning a trip. A guide:  The federal government is constantly monitoring beaches along the Gulf for oil that has washed up from he spill. It reports which beaches have no oil observed, negligible to heavy tar balls, and very light to heavy exposure to oil.  Large amounts of oil from beneath the Gulf's floor seep out naturally. One estimate pegs the average amount at roughly 1 million barrels per year. That helps explain why, long before this spill, Gulf beachgoers have seen the weathered chunks of oil known as tar balls wash up on the sand.  Spilled oil's toxicity—and its smell—depends on many factors, including how long the oil has been in the water. The particularly toxic components of oil, known as aromatic hydrocarbons, can evaporate within hours or days of a spill. After that, oil continues to lose toxicity, through exposure to sun, wind and waves—a process known as weathering. But even tar balls can contain fresher globs of oil inside, scientists say.  Public health officials warn swimmers to avoid oily water, which can cause skin and eye irritation. Even if you don't see oil on the water's surface, it doesn't necessarily mean the water is oil-free. Last week, researchers for the federal government and BP found oil lurking underwater not far from the beach near the Alabama-Florida border, though they'd seen no oil on the water's surface.  Hurricane season in the Gulf started June 1. Depending on how a hurricane hits, scientists say, it could help the spill cleanup by further breaking up the surface slick, or it could intensify the damage by pushing more oil ashore.  "We've seen quite a difference," says Steven Pereyra, co-owner of the Topp Dogg Guide Service, which takes tourists to fish for redfish and speckled trout, and reports business is up roughly 50%.  As far south as Corpus Christi and South Padre Island, Texas hotel managers and tourism officials say they're experiencing increased visits from tourists who typically vacation in Alabama or Florida. However, Texas tourists learned this week that leisure time there can also be abruptly interrupted: Many vacated hotels on South Padre Island amid forecasts that Alex was headed their way.  Mississippi tourism authorities launched a $4 million advertising campaign in May highlighting that its 26 miles of beaches remained pristine. It tweaked that message in its newest $11 million campaign, launched this week, to trumpet non-beach activities such as its 11 coastal casinos.  The 1740-room Beau Rivage Resort & Casino on Biloxi's beach says the oil spill hasn't had a significant impact on its business yet. But it's also offering promotional packages to sway wary out-of-state travelers—including roundtrip airfare from Atlanta and two nights at the resort for as little as $99 per person.  Tourism at Alabama's normally busy beach resorts is down roughly 50% and some local eateries are having to get creative in response to seafood shortages. Wintzell's Oyster House, a popular restaurant chain, still serves Gulf oysters, but stopped offering them at half price during happy hour. On the menu instead: 25-cent chicken wings.  "We've had people offer hair'' to help soak up the oil spill, said Mike Foster, vice president of marketing at the Alabama Gulf Coast Convention & Visitors Bureau. "If you really want to help us, come down and spend a week with us.''  In Alabama, tourism officials have a channel on YouTube beaming daily video feeds from local beaches to convince tourists that oil intrusions are scattered. Video hostess Rebecca Wilson recently talked up "Captain Crunch," a 13-foot, 800-pound alligator with the "world's strongest bite ever recorded" at a nearby farm called Alligator Alley. "Margaritaville" musician Jimmy Buffett is giving a free concert in Gulf Shores July 11.  In the Florida Panhandle, a free concert featuring Kenny Loggins and the Doobie Brothers was held last weekend on Fort Walton Beach. In neighboring Destin, Newman-Dailey Resort Properties is offering a 15% discount for the July 4 weekend after occupancy rates at its 200 rental units recently fell as much as 30%. To ease worries, the company also is returning deposit fees to visitors who have second thoughts.  Far from the affected beach towns, but still suffering from the bad PR, Sarasota is offering free ice cream at its visitors' center for the rest of the summer.  Still, if any tourist-focused businesses in Florida are enjoying this summer, they're likely to be found inland or on the Atlantic coast.  In Orlando, the theme-park hub about an hour-and-a-half drive from the Gulf Coast, tourism officials are forecasting stronger revenue than last summer. That's partly because the June 18 opening of a new Harry Potter theme park at Universal Orlando Resort is "drawing quite a crowd,'" said Danielle Courtenay of the city's convention and visitors bureau.  Farther north on the Atlantic coast, the Amelia Island Plantation resort says July reservations are 7% ahead of last year's pace. "We're definitely seeing great numbers this summer,'' says Amy Lacroix, the resort's marketing manager. That includes 45 reservations from guests who cited their desire to avoid the oil spill in the Gulf.  Write to Miguel Bustillo at miguel.bustillo@wsj.com and Mike Esterl at mike.esterl@wsj.com
Can you have a great vacation in the Gulf Coast? It all depends how much beach fun you require—and your appetite for risk.