COLUMBIA -- Owners of some of the state's most pricey oceanfront property hope the Legislature will spare them from new beach setback lines that they say could make it tougher to sell or rebuild after a hurricane.

The House could take up a measure today that would exempt Fripp Island from new setback rules.

Regulators say they're treating Fripp Island no differently from any other coastal community. They say the Fripp bill is the first time the Legislature has gone this far to intrude on the state's policy of restricting building in erosion-prone coastal areas.

Fripp is a privately owned, 3,000-acre island in Beaufort County. Visitors must pass a security guard and cross a private bridge to view houses that mostly sell for well over $1 million. Piles of rocks called a revetment keep the crashing Atlantic Ocean surf from stealing land.

But it's what can be seen only on maps that irks the owners of miles of beach-front property: the new setback line that crosses decks and living rooms, and puts entire houses and condo buildings on much of the island on the wrong side of the state's decades-long policy to discourage beach-front building in areas prone to erosion.

"It's totally ridiculous," said Edward Dukes, a real estate broker who owns one of the houses on the wrong side of the thin blue line drawn on maps adopted by the state's Ocean and Coastal Resource Management office. "The most ridiculous part is in an economy like this, we're all spending money on lawyers when there's a rock revetment."

It shouldn't be that way, said Mary Shahid, a Charleston lawyer representing the Fripp Island Property Owners Association.

The new setback lines went into effect in October, and Shahid is challenging them for the association in the state's administrative court system.

It's the only barrier island on the coast that has its waterfront all lined with rock, Shahid said, adding "That place is a fortress."

But it is unclear how strong it is, said Carolyn Boltin-Kelly, OCRM's deputy commissioner. "The actual erosion control structure at Fripp has never been tested in a major storm," Boltin-Kelly said. "It almost gives a false sense of security to the property owners that the revetment can protect against a big storm."

Similar stonework failed in other states in bad storms, she noted. State law won't allow Fripp property owners to replace that structure if it fails. And that's one of the reasons setback lines were moved inland, Boltin-Kelly said.

Previously the line was at the revetment itself. Regulators moved it inland based on erosion threats as if the stone protection wasn't there. The version of the bill that the House will debate moves the setback line 20 feet inland while the original Senate version kept the stone revetment as the line.

Meanwhile, the erosion threat assessment at Fripp and other parts of the state that occurs every eight to 10 years now also includes longer-term data on erosion patterns.

"We're using the same process for Fripp that we're using for the entire state," Boltin-Kelly said.

Shahid questions the reliability of some of that information, including data based on high-water marks. She favors instead sticking with the aerial photography at the heart of the old setback lines.

Dukes said the setback line can make it tougher to sell property. Those with the setback line drawn through them will be tougher to sell than those without, Dukes said.

That's not been the case in research OCRM has done, Boltin-Kelly said.

Boltin-Kelly sees the Fripp legislative episode as a challenge to her agency's role.

"We believe we should be setting the lines based on historical and scientific data and not having the General Assembly set the base line and the setback line," Boltin-Kelly said.

There's no reason for Fripp to be treated differently from any other coastal community, she noted. And if the Legislature takes that route, "it could potentially lead to other communities wanting the same thing."