These here are the remnants of the H. L. Hunley, a Confederate submarine from the Civil War. Reuters has an excellent article about it:
Scientists have found the vessel to be a more sophisticated feat of engineering than historians had thought, said Michael Drews, director of Clemson’s Warren Lasch Conservation Center.
“It has the ballast tanks fore and aft, the dive planes were counterbalanced, the propeller was shrouded,” Drews said. “It’s just got all of the elements that the modern submarines have, updated.”
MSNBC’s Photoblog has a few photos of it, including the one accompanying this post, taken by Bruce Smith for the AP.