In February 1864, the H.L. Hunley became the first combat submarine to sink an enemy ship. Then, for reasons that remain unclear, it sank to the bottom of Charleston Harbor.
What would have happened if, instead of sinking, the Hunley and its crew had gone on to sink more of the ships that formed the Union blockade of Charleston? Could the Confederate secret weapon have helped turn the tide of the American Civil War, or at least delayed the inevitable?
Michael Scafuri, an archaeologist working on the conservation of the Hunley for the Clemson University Restoration Institute, says that while the initial submarine attack on the USS Housatonic caught the Union Navy off guard, the scope of the Hunley's usefulness was limited. The sub's spar-mounted torpedo system proved useful against a wood-hulled ship, but it likely would not have sunk the ironclad ships that made up the rest of the blockade.
"They could have gone back out subsequent days and attempted to sink another ship. The question is going to be, of course, how well would the Union Navy blockade fleet respond to this?" Scafuri says. "It might have taken them time to figure out what happened and how it happened. So, best-case scenario, it could have gone out and sunk another ship or two."
Scafuri reminds us that, even among some of the Confederate military leadership, the Hunley was not a popular ship. Before February 1864, the sub had already sunk twice during training exercises, killing 13 Confederate soldiers in the process. "It was an interesting, revolutionary concept that never had the time to come into its own," Scafuri says. But if Lt. George E. Dixon and his crew had returned victorious instead of sinking to their watery grave, Scafuri says the history of military technology might have shifted.
"If it had been successful and actually caused the Union Navy to redeploy or change their tactics a bit, it would have been something that brought more attention to the whole idea and use of submarine warfare and could have had an impact on the development of naval technology in the late 19th century," Scafuri says.
In the scope of the war, though, Scafuri says the Hunley was "a little too little, a little too late." He compares the emergence of the technology to the V-2 rocket, which Germany used only in the final year of World War II.
"It just shows you in times of war that expediency and desperation will often force inspiration," Scafuri says. "If you're winning, there's no real reason to change. If you're losing, you have more motivation to try some new and extreme things, like throwing out jet fighters or being willing to give submarines a shot."