Keelhauling was a form of punishment for sailors at sea. The sailor was tied to a rope looped beneath the vessel, thrown overboard, and then dragged under the keel and up the other side.
Keelhauling was generally a death sentence since it could take as
long as three minutes, and perhaps longer, to
walk the ropes all the way back to the stern. Often the ropes caught and dragged on barnacles on the
ship's hull: the barnacles ripped the victim's clothing and
skin to shreds as he was dragged along.