Why Sailors Never Say 'Pig' or Sail on Fridays

For centuries, sailors have followed a peculiar code of conduct at sea—one governed not by logic, but by superstition. These maritime taboos were taken deadly seriously, with captains sometimes delaying voyages for an entire day just to avoid leaving port on a Friday.

The Dreaded Friday Departure

Friday is perhaps the most enduring sailing superstition. Admiral William Henry Smyth described it in 1867 as "the Dies Infaustus, on which old seamen were desirous of not getting under weigh, as ill-omened." The origins trace back to Christianity—Christ was crucified on a Friday—and to Norse mythology, where Friday was named after the goddess Frigga, later demonized as a witch by early Christians.

The superstition was so powerful that even during World War II, U.S. Navy ships were sometimes delayed for important missions to avoid departing on a Friday. A famous urban legend claims the British Admiralty tried to debunk this nonsense by commissioning HMS Friday—laid on a Friday, launched on a Friday, captained by James Friday, and sent to sea on Friday the 13th. The ship was allegedly never seen again. (Though this story is almost certainly apocryphal, it illustrates how deeply the belief ran.)

The Word You Can Never Say

Mentioning pigs aboard ship was strictly forbidden. The taboo was so strong that an entire book exists titled Never Say P*g: The Book of Sailors' Superstitions. Ironically, images of pigs were considered good luck—sailors often tattooed pigs and roosters on their feet, believing these animals would guide them to shore if they drowned, since livestock in wooden crates often floated and survived shipwrecks.

Green, Knives, and Upside-Down Hatches

Green was the color sailors feared most. Some believed it represented land, warning of running aground. Others thought it symbolized the mold that rotted wooden ships, or the blue-green tinge of drowned corpses. Either way, green clothing or objects were banned from many vessels.

Sticking a knife into the deck was another offense—it invited bad luck, though the exact reasoning has been lost to time. Stirring tea with a knife or fork was similarly taboo.

Perhaps the most vivid superstition involved hatch covers. Leaving one upside-down was seen as a premonition of an upside-down boat—a ship capsized and sinking. Some captains refused to tolerate this even for a moment. Dropping a hatch into the hold was considered even worse.

Why Did Sailors Believe?

Life at sea was brutal and unpredictable. Storms could appear from nowhere, ships could vanish without explanation, and death was always close. In a world with no weather forecasts or GPS, superstitions gave sailors a sense of control. If you followed the rules—avoided Fridays, never said "pig," kept green off the ship—maybe you'd make it home.

These beliefs weren't just quirks. They were survival rituals, passed down through generations of men who'd watched the sea claim their friends. In that context, a little superstition seemed like cheap insurance.