First ship sunk by a submarine

The US Civil War Confederate ship H.L. Hunley became the first submarine ever to sink another vessel during wartime, when she successfully 'torpedoed' the Union Navy's Housatonic off Charleston Harbour, South Carolina, on 17 February 1864. The 12 m (40 ft) long sub was powered by a propeller that was attached to a crankshaft turned by a crew of seven, who endured claustraphobic conditions in a cabin just 1.2 m (4 ft) tall and 1.06 m (3½ ft) wide. Hunley would generally remain close to the surface, with air being supplied through two 'snorkels' operated by bellows. The 'torpedo' consisted of a barrel of gunpowder attached to a 6 m (20 ft) spear at the front of Hunley. The idea was that the sub would ram an enemy ship, embedding the spear in its hull whilst the sub backed off. The charge was detonated remotely by pulling a rope.