A new documentary on the Hunley project will air Thursday night.

The National Geographic Channel will debut "Secret Weapon of the Confederacy" at 9 p.m. The show will delve into possible theories about why the Confederate submarine disappeared shortly after sinking the USS Housatonic, which was the first successful submarine attack in history.

"The Hunley represents one of the world's most intriguing maritime mysteries. Using the latest discoveries emerging from the Project, we attempted to capture the fascination surrounding the submarine in a compelling documentary," said Producer and Director Alan Martin.

For more information, go to www.natgeotv.com.