3. Horace Lawson Hunley invented a submarine to fight the Union in the American Civil War and died inside it
Submariners have long been credited with being the bravest of all seafarers. And this was especially true in the earliest days of underwater exploration. Horace Lawson Hunley was a true pioneer, inventing the very first combat submarine during the American Civil War. He named the vessel after himself and oversaw all the testing of the H.L. Hunley. It was far from plain sailing. In October of 1863, five Confederate soldiers recruited to man the first boat died when a passing boat caused waves that flooded in through some open hatched. Dismayed but not beaten, Hunley decided to put himself forward for future testing.
Hunley was one of a crew of 8 who died when the prototype submarine sank just days after that first accident. However, the submarine itself was recovered and, with the holes patched up, re-launched soon after. In 1864, history was made when the H.L. Hunley carried out the first successful sinking of an enemy vessel, the Union ship USS Housatonic. Even that success came at a price, however, with all the crew killed when the sub sank whilst returning from the mission. Despite the setbacks, Hunley is still remembered as a true naval warfare pioneer.