Date:28 February 2012
When he was a kid, Chris Southerly wanted to try scuba diving – but the mountains of Virginia, where he grew up, offered few opportunities. So Southerly learned to dive in graduate school, and now it’s how he makes his living. As an underwater archaeologist for North Carolina’s Department of Cultural Resources, Southerly is currently excavating the infamous pirate Blackbeard’s flagship, Queen Anne’s Revenge, near Beaufort Inlet, North Carolina. When he’s not diving to the wreck, he’s examining artefacts from the ship to figure out how they fit into people’s lives. “An artefact is a tangible connection to our history,” he says. “It’s one thing to read about it in a book. It’s a whole other experience to hold it in your hand knowing that you’re the first person to see or touch this object in nearly three centuries.” – Mary Beth Griggs
Name: Chris Southerly
Years on job: 11
Full face mask
“In many cases, the waters we’re working in have zero visibility,” Southerly says. To communicate with fellow divers and the surface crew, he uses scuba gear with a full face mask. Unlike typical scuba equipment, which requires a diver to breathe through a mouthpiece, the mask allows Southerly to talk to other divers up to 45 m away via a radio link.
After using sonar to identify a site, archaeologists deploy portable magnetometers that detect the presence of iron under layers of sediment to pinpoint the best spots for excavation. “Detecting range is based on distance from the object and the magnetic disturbance it causes,” Southerly says. “A cannon might be detectable from 4,5 metres, whereas a cannonball may be detectable only from 1,5 metres.”
Hammer and stakes
“Archaeology is a destructive science,” Southerly says. ”Once we dig it up, we can never put it back the way it was.” Without context, artefacts are nearly worthless, so archaeologists document the site meticulously. Using stakes and synthetic decking boards, they create a 1,5 x 1,5 m grid on the seafloor, then they map the location of the artefacts on waterproof paper.
Southerly uses a suction tube to remove small items from the wreck to a sluice, or artificial water channel, on the ship’s deck. Sand and mud fl ow with the water until they are discharged at the end of the sluice; heavier artefacts, such as nails or shotgun pellets, drop out of the fl ow into a separate channel, where they’re identified and labelled. Larger items are hoisted up with an electric winch after they’ve been tagged and mapped on the seafloor.
Video: Watch the Historic raising of Blackbeard’s sunken anchor for more details.