Also known as a “Crossing the Line” ceremony, this irreverent tradition originated more than 400 years ago and was popularized by the crews of European naval ships and merchant marines that crisscrossed the equator in the 19th and 20th centuries, when global ocean journeys became routine. The tradition has a rich history that draws from mythology and diverse naval traditions, some darker and more violent than others. Originally conceived as a way to test new recruits (or simply to boost morale on long voyages), the ceremony pits seasoned sailors, or “Shellbacks”—also known as “Sons of Neptune”—against the newbie “Pollywogs” in the crew during a 24-hour ceremony. Although the tradition no longer features beatings or physical abuse, part of its lasting appeal is the ritual teasing that Pollywogs endure before being named Sons or Daughters of Neptune. The fun parts of the ceremony continue—such as inverting roles, pulling pranks, staging mock trials and enduring silly tests—so if you’re lucky enough to cross the equator, you’ll have a chance to watch your crew participate in this amusing rite.