There's a dirty secret buried under Gulf of Mexico beaches after cleanup workers scrape away the oil washing ashore.

Walk to a seemingly pristine patch of sand, plop down in a chair and start digging with your bare feet, like everyone does at the beach. Chances are you'll walk away with gooey tar between your toes.

So far, cleanup workers hired by BP have skimmed only the surface, using shovels or sifting machines to remove oil. The company is planning a deeper cleaning program that could include washing or incinerating sand once the leak is stopped.

Some experts question whether it's better to just leave it alone and let nature run its course, in part because oil that weathers on beaches isn't considered as much of a health hazard as fresh crude. Some environmentalists and local officials fret about harm to the ecosystem and tourism.

"We have to have sand that is just as clean as it was before the spill," said Tony Kennon, the mayor of Orange Beach, a popular tourist stretch reaching to the Florida state line.

On Wednesday, choppy seas held up oil skimming operations all along the gulf coast, although boats off Louisiana's shoreline hoped to be back at work before the day ended. Rough waves have halted offshore skimming in Mississippi, Florida and Louisiana for more than a week.

Orange Beach was stained Wednesday by a new wave of tar balls and brown, oil-stained foam.

BP says it hopes to clean it all eventually. Mark DeVries, BP's deputy incident commander in Mobile, envisions a time when no one can tell what hit the beaches during the summer of oil. "We're referring to it as polishing the beaches," he said.

Chuck Kelly, who works at Gulf State Park, knows what a job that will be.

"Some oil comes in with a wave, and another wave covers it with sand," he said. "It's just like a rock or a shell. There's all sorts of things buried in this sand. Now, there's oil."

George Crozier, a marine scientist and director of the Dauphin Island Sea Lab, said there's only one real reason to dig up the buried oil: tourism.

"Buried is buried. It will get carved up by a hurricane at some point, but I see no particular advantage to digging it up," he said. "It's a human environmental hazard only because people don't want to go to the beach if it's got tar balls on it."