Horace Lawson Hunley (died 1863)

Hunley was a marine engineer and designed and created hand powered submarines for the Confederate army. As you can imagine, making and testing a submarine  is a pretty risky business.

Whilst trialing one of his inventions, five of his crew mates drowned when a passing ship’s wake flooded into their open hatches. Undeterred Hunley continued his submarine inventing mission. During his last trial he took command of the experimental vessel himself. The machine never resurfaced killing all eight men inside.

The submarine of death was recovered and reused. It in fact became the first submarine to ever sink an enemy vessel in naval history, before sinking itself once again.