Pirate flags were on the ships. The flag was called the Jolly Roger. The flag had a skull and bones or a hourglass. The hourglass ment your time is running out. The Jolly Roger is the name now given to any of various flags flown to identify a ship's crew as pirates. The most famous Jolly Roger today is the Skull and Crossbones, a skull over two long bones set in an X arrangement on a black field. Historically, the flag was flown to induce pirates' enemies to surrender