Did copper sheathing make keel-hauling safer by removing barnacles?
Short answerNo clear safety gain followed: the smoother hull reduced scraping but increased speed through the water, which may have made drowning more likely.
NotesCopper sheathing reduced barnacle growth and made a warship's hull move more efficiently through the water. A person dragged beneath a moving coppered ship might therefore avoid some cutting from barnacles while being pulled farther underwater before reaching the other side. The suggested tradeoff remains an untested theory: drowning could occur sooner even if the hull caused fewer abrasions. A technical improvement to the ship did not make this dangerous punishment humane.