Bruce Smith / AP
The Confederate submarine H.L. Hunley sits in a conservation tank at a lab in North Charleston, S.C., before it was to be covered in a chemical bath on Thursday, May 1, 2014. Bathing the hand-cranked Hunley in chemicals marks a new step in the conservation of the first sub in history to sink an enemy warship. The chemical bath will help remove salts and the encrustation on the submarine's hull. The Hunley sank a Union blockade ship off the South Carolina coast in 1864. It was discovered in 1995 and raised in 2000 and brought to the North Charleston lab.