Researchers and archaeologists from the Underwater Archaeology Branch of the North Carolina Office of State Archaeology and the Institute of International Maritime Research were conducting sonar operations late last month when they spotted the sunken hull of a wooden steamer ship in the Atlantic Ocean near Oak Island. Experts are now working to identify the vessel, but evidence suggests it is one of several Confederate blockade runners used to penetrate the wall of Union ships blocking the vital port of Wilmington during the Civil War.

Just six days after the fall of Fort Sumter in April 1861, President Abraham Lincoln issued a proclamation declaring a naval blockade of the southern coast stretching from South Carolina to Texas (it was later extended north to North Carolina and Virginia). For the remainder of the Civil War, the Union blockade aimed to keep much-needed supplies from reaching Confederate ports, and to prevent the export of cotton and other valuable goods that would fund the Confederate war effort.

Soon after the blockade was put into place, Confederate blockade runners hit the water. These slim, speedy ships represented the most advanced maritime technology of the day, and they did a lucrative (if risky) business ferrying both war materiel and consumer goods through the wall of Union ships. Blockade runners were usually unarmed, and were often painted a pale grey in order to remain as unobtrusive as possible.

The Confederate blockade runner ‘Sumter’. (Credit: MPI/Getty Images)

The shipwreck discovered off the coast of North Carolina on February 27 is the first Civil War-era vessel to be found in the area in decades. Researchers on the vessel Atlantic Surveyor recorded the ship’s hull, buried 18 to 20 feet below the ocean’s surface and located 27 miles downstream from Wilmington at the mouth of the Cape Fear River, near Fort Caswell. “The state of preservation on this wreck is among the best we’ve ever had,” underwater archaeologist Billy Ray Morris said in a statement released by the North Carolina Department of Natural and Cultural Resources.

Morris and other researchers are now working to identify the vessel as part of a series of operations funded by the National Park Service through the American Battlefield Protection Program. Earlier this week, a pair of divers explored the wreck, while Morris monitored their activity from a nearby boat. Visibility was poor, but the divers were aided by the detailed sonar image of the wreck.

So far, all the available evidence—including historical accounts, sonar images and the divers’ work—appears to indicate the newly discovered shipwreck is the Agnes E. Fry, one of three blockade runners known to have run around in the region. The wrecked ship is the closest in length to the Fry, and divers confirmed the ship’s boilers was of the same type that would have been used on a ship built in Glasgow, Scotland circa 1864. (The Fry was constructed that year on Scotland’s River Clyde.) The other two runners lost in the vicinity, the Spunkie and the Georgianna McCaw, are smaller and of an earlier design. Originally christened the Fox, the Fry was renamed after being purchased by the blockade running company, in honor of the ship captain’s wife. According to historical accounts, the ship did business in Havana, Cuba, and could have also visited other neutral ports in Bermuda and the Bahamas.

Union forces captured Fort Fisher in January 1865, leading to the fall of Wilmington and the capture of a key Confederate railroad line. According to Morris, the crew of the Fry ran the ship aground rather than see it fall into enemy hands. In all, there are believed to be some 27 wrecks—including both Union and Confederate ships—associated with the Wilmington-Fort Fisher campaign located in the area, including eight that have not been found.

Though there might be some cargo left onboard the wrecked ship, Morris told CNN he doesn’t know what the Fry might have been carrying on its last voyage, and his first priority is to positively identify the vessel. Any artifacts or ship parts brought to the surface will be solely for investigative purposes, as researchers attempt to learn more about this “state of the art blockade runner” and the technology used to build it.