The story
On an old sailing ship, the deck had openings called hatchways, or hatches, that led down into the hold.
When a storm was coming, that would not do. Waves breaking over the deck could pour straight down the hatches and swamp the ship. So the crew covered them with heavy tarpaulins—canvas made waterproof with tar.
A strong wind could tear the canvas loose, so the sailors nailed narrow wooden strips, called battens, around the edges. Hammers rang across the deck as the sky darkened. In 1769, William Falconer’s Universal Dictionary of the Marine explained that “The battens serve to confine the edges of the tarpaulins close down to the sides of the hatches.”
The full shout appears in print in 1883, in Chambers’s Journal: “Batten down the hatches—quick, men.” From there it was a short trip to dry land. Anyone bracing for a hard stretch could batten down the hatches.
