Safe Water

“Steamboat pilots needed help in shallow water. A man would stand at the bow of the boat with a lead weight tied to a rope. Knots were tied at intervals. The weight would be tossed out in front and when pulling on the rope reached a vertical, the knots reflected how deep the water was. A mark was like a fathom on the ocean or six feet. Twain means ‘two.’ If the leadsman called out ‘Mark Twain’, it signified twelve feet or safe water. This is the origin of Samuel Clemens’s pen name ‘Mark Twain’.”