Mitchell Colgan, a College of Charleston geologist, and the S.C. Coastal Conservation League’s Hamilton Davis said the legislation seems politically motivated. Exploration off the coast in the 1970s and 1980s revealed little oil. The amount of oil that could be squeezed from the ocean would be a tiny percentage of what states like Alaska and Texas produce, Colgan said.

Natural gas that does exist is in a form that is hard to extract, he said.

“The only people clamoring for offshore drilling in South Carolina are the politicians,’’ said Colgan, who formerly worked for the Shell oil company. “You don’t see Shell or Exxon or the other major oil companies interested in what we have offshore. For South Carolina to talk drilling for oil, it’s political and not scientific.’’

Officials with the S.C. Small Business Chamber of Commerce also voiced reservations. But Graham, who said he also backs alternate energy development, said his idea only makes sense.

He blamed President Barack Obama for failing to move aggressively to pursue offshore oil and gas reserves. He said the oil and gas industry could provide thousands of jobs, more than the Boeing aircraft plant in North Charleston and the BMW car manufacturer in the Greenville area.

“Off the coast of South Carolina, we have oil and gas deposits ... that will allow this nation to become more energy independent, that would create more jobs in South Carolina than Boeing and BMW combined, and would because of the nature of the legislation create a revenue stream for the state of South Carolina.”

Those backing the Graham plan include representatives of some of the state’s biggest business organizations, including the S.C. Chamber of Commerce. An estimated 150 people attended a luncheon at Saluda’s restaurant to discuss the plan after Graham’s news conference.

The Associated Press contributed.