Keelhauling

The act of keelhauling was to haul someone under the keel of a ship as punishment or torture. The sailor was tied to a line looped beneath the vessel, thrown overboard on one side of the ship, and dragged under the ship's keel, either from one side of the ship to the other, or the length of the ship. This resulted in severe lacerations and infection from barnacle growth on the hull, if they didn't drown first. It was lastly documented in 1882 where two Egyptian sailors were punished by keelhauling near the city of Alexandria.