FOLLY BEACH -- Huge swells from Hurricane Earl pounded Lowcountry beaches Thursday, awing the people who thronged to watch. But the wash stripped tons of sand from renourished beaches.

The west end of Folly Beach, a Charleston County Park and Recreation Commission public beach, was among the sites that eroded significantly during the afternoon high tide, said Dan Burger, S.C. Ocean and Coastal Resources Management communications director.

"The beaches definitely have lost a lot of sand," he said. The agency will work with local government today to get a fuller assessment of the damage, he said.

The faces of waves breaking at high tide at the Folly Beach Washout were 10- and 12-feet high. The breakers washed torrents of foam past the walk-overs at the rock wall, surged the rocks at points and swept onto the road.

The wash swept away sand so fiercely that a nearly buried rock jetty on the east end of the island was exposed chest high by late afternoon. Mike Criss, vacationing from Knoxville, Tenn., set up a beach umbrella in the dunes to watch as high tide approached, then moved back to a raised walkway when it nearly carried him off.

He tried to body surf once and was "roped, tossed and beaten up," he said. He came away digging sand out of his ears.

Tom O'Rourke, executive director of the Charleston County Park and Recreation Commission, said that a small sailboat went out from Folly Beach about 3 p.m. and crashed into the pier. The sailboat was "literally cut in half," he said, but no one was injured. Nothing happened to the pier, which is solid and sturdy, he said. "A couple years ago, a gigantic barge hit it" and nothing happened to it, he said.

O'Rourke said his big worry Thursday night was about beach erosion. "I can't imagine what it's going to look like in the morning," he said.

Axel Reinert stood on a walk-over at the Washout as the tide wash hissed beneath him Thursday afternoon. The seas were the most powerful seen in at least five years, he said. The Washout was packed with cars and people carrying surfboards, but nearly all of them stayed on the rocks. Around him, people oohed as someone lost a board in the surf and it snapped in half.

"This place usually has 500 people out there in the summertime. How many people do you see out there now? Ten?" Reinert said. He's been surfing since 1974 but wasn't even in his swimsuit. "I'm 49 years old. I don't want to die today."

The National Weather Service has a high surf advisory in effect through 6 a.m. today. Breakers should drop to less than 5 feet later in the morning.

"This will last all night," Reinert said marvelling, "and tomorrow morning will be clean and glassy."

Diane Knich contributed to this report. Reach Bo Petersen at 843-937-5744 or bpetersen @postandcourier.com.