Keelhauling (Dutch kielhalen;[1] "to drag along the keel") is a form of punishment and potential execution once meted out to sailors at sea. 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 (from bow to stern).
- ^ "Etymological origins". etymonline.com. Retrieved 9 August 2018.