Since the special equipment used for the sake extraction is called fune (written as 槽 in Japanese), whose pronunciation is the same as another Japanese word 船 (which means "a boat" or "a ship"), this position is called sendo (waterman), representing the captain of a ship.
搾りに使う酒造具を槽（ふね）と呼ぶことから、船（ふね）とかけて、その長として船頭と呼ぶ。