Porch Construction in Isle of Palms, SC

ISLE OF PALMS, S.C. (WCSC) — As beach days return to the Lowcountry, a delicate balancing act is underway on the Isle of Palms, where efforts to combat coastal erosion must contend with Civil War history resting just offshore.

About a mile out in murky Atlantic waters lie the remains of ships sunk more than 160 years ago. They were part of the Union Navy’s effort to choke off Charleston during the Civil War. Today, those same wrecks are shaping how engineers restore the island’s eroding shoreline.

In a quiet basement lab at the South Carolina Institute of Archaeology and Anthropology at the University of South Carolina in Columbia, toothbrushes, teacups, ceramics, bullets and even bones sit carefully cataloged in boxes.

They are artifacts recovered from blockade runners and vessels connected to what became known as the First and Second Stone Fleets.

“During the Civil War, the Union Navy instituted a blockade of Southern ports. In South Carolina, that really manifested in Charleston trying to prevent blockade runners from coming in,” James Spirek, state underwater archaeologist, said. “The blockade runners are bringing military goods and then also commercial goods, consumer goods to the South and to keep the army going.”

To strengthen the blockade, the Union purchased aging whaling and merchant vessels, filled them with stone, and deliberately sank them in key shipping channels leading into Charleston Harbor. The first fleet obstructed the main ship channel. When runners adapted, a second wave of ships was sunk off what is now the Isle of Palms.

“It was an obstacle course,” Spirek said.

Smugglers still tried to slip through the shallow beach channels. Some didn’t make it.

“The Georgiana, in this case, it’s spotted and it’s chased by the Union by and the blockade was, you know, firing heavy cannons at it. And so apparently it did disable the vessel. And then the captain, the Georgiana, wrecked onto a shoal.”

A year later, another ship, the Mary Bowers, wrecked onto the Georgiana. On sonar scans, the two form an X on the seafloor.

“And so we, you know, like to say that X truly marks the spot,” Spirek said.

Divers who first documented the wrecks in the 1960s described murky water and cargo seemingly frozen in time. When archaeologists returned decades later, visibility remained limited, sometimes only a few feet.

But even in dark water, history is visible.

“There’s still information out there and it’s amazing what can be preserved,” Spirek said.

He calls the wrecks “nonrenewable resources.”

“We’re not going to get, hopefully, another American Civil War,” Spirek said. “So these things are never going to be made or anything of that nature. So that’s why we look to preserve them.”

While history rests offshore, erosion is eating away at the island’s shoreline. The U.S. Army Corps of Engineers and the city of Isle of Palms are planning a major beach renourishment project expected to begin this summer, with an estimated cost of $30 million.

“If we don’t restore the beaches, the erosion starts to threaten the critical infrastructure: homes, buildings, parking areas, public use areas. And then we end up with a lot of storm damage,” Steven Traynum, president of Coastal Science and Engineering, said.

Beach renourishment involves dredging sand from offshore and pumping it onto the shoreline. But not just any sand will do.

“Beach sand has to be a certain character. It’s got a certain grain size, certain color or certain texture. And we try it when we’re doing dredging projects and beach restoration. We’re trying to match the native sand as much as we possibly can,” Traynum said.

Some of the best beach-quality sand sits near the historic wreck sites.

“We’re trying to avoid the, the most critical area where we know most of the wrecks are, even though there’s some really good sand there,” Traynum said.

Removing too much sand near a wreck could destabilize it. Changing currents could scour away protective sediment, exposing fragile wood hulls to faster deterioration. To prevent that, archaeologists and engineers establish buffer zones, essentially invisible circles around known shipwrecks and magnetic anomalies.

“If it’s a known shipwreck where you know what the ship is, we put a very large buffer around that because we don’t want to get anywhere close,” Traynum explained.

Spirek says the process is rooted in federal law when federal funding is involved, requiring consultation and cultural resource surveys before dredging begins. If something significant is found, work can be adjusted.

For engineers, it’s about stewardship as much as construction.

“The worst thing we want to see is a historic artifact come through that dredge pipe,” Traynum said.

Ironically, ships once sunk to blockade Charleston are still influencing the coastline today.

Spirek notes that in previous debates over renourishment, headlines joked that the Stone Fleet was “still blockading” the coast.

More than 160 years later, the obstruction is no longer military; it’s historical.

“It’s really just a balance. I don’t see why we need to just blow through shipwrecks just because they’re in the way,” Spirek said.

Above water, waves continue their slow work of reshaping the shoreline. Below, wooden hulls rest in sand and shadow, remnants of a naval battlefield few beachgoers will ever see. The challenge for the Isle of Palms is not choosing between beach and history: it’s protecting both.