On the night of February 17, 1864, the Confederate submarine H.L. Hunley became the first submarine in history to sink an enemy warship. It then disappeared — and was not found for 131 years.

The Machine

The Hunley was 40 feet long, four feet in diameter, and hand-cranked by a crew of eight men turning a crankshaft connected to a propeller. It could submerge by flooding ballast tanks and had a timed mechanism to blow air through the tanks for surfacing. Power came entirely from human muscle. Speed was approximately four knots on the surface, less below.

It had already killed two crews in trials before it was sent against the Union blockading fleet outside Charleston Harbor.

The Attack

The USS Housatonic was a 1,240-ton sloop-of-war anchored in five fathoms of water outside Charleston. On the evening of February 17, her lookouts spotted something in the water approaching — low, dark, moving. The crew beat to quarters and attempted to maneuver, but the Hunley was already alongside.

The Hunley's weapon was a spar torpedo — an explosive charge mounted on a 17-foot pole extending from the bow. She drove the torpedo into the Housatonic's hull and backed away. The charge exploded. The Housatonic sank in about five minutes. Five of her crew died; the remainder escaped into the rigging above the waterline.

The Hunley signaled shore with a blue light and then vanished.

The Mystery

The submarine was found in 1995 by a team led by author Clive Cussler, buried in sediment about a thousand yards from the Housatonic's wreck site. She was raised in 2000 and is now undergoing conservation in a tank of fresh water in North Charleston, South Carolina.

Analysis of the crew's remains showed no signs of panic or emergency action — the men died at their stations, in postures suggesting they expected to surface. Forensic investigation suggests the concussion from the torpedo explosion, transmitted through the water, may have fatally injured the crew without visibly damaging the submarine.

The Hunley sank an enemy warship, signaled success, and then simply stopped. The eight men inside never made it home.

They were buried with full Confederate military honors in 2004 — 140 years after their deaths. An estimated 40,000 people lined the streets of Charleston for the procession.