It was February 17, 1864. The USS Housatonic floated in Charleston Harbor atop calm, cold waters. Below the surface, a group of Confederate soldiers sweated bullets as they cranked the propellers of the H. L. Hunley, speeding toward the Union's Housatonic on a historic mission: they would become the first submarine crew ever to sink an enemy ship. A 135-pound torpedo struck the Housatonic's stern, detonating a fiery explosion that sank the vessel within minutes. The Hunley then surfaced just long enough for the crew to flash a blue light, signaling to fellow forces on the shore that the mission succeeded and the submarine would return. And it did—but not until almost 140 years later, when it was raised from the harbor's sandy bottom on August 8, 2000, after author Clive Cussler discovered the wreck intact.

Today, the friends of the H. L. Hunley Submarine seek to conserve, restore, and ultimately exhibit this historic vessel, as well as solve the mystery of how it completed its mission only to vanish moments later. They welcome visitors to see the submarine in its current condition—within a 75,000-gallon conservation tank—and educate guests on the vessel's many details.