If you sail the seven seas long enough, you may be invited to King Neptune’s Court.

The line-crossing ceremony occurs every time a ship crosses the equator. The ship’s passengers and crew are divided into pollywogs (the uninitiated who have never crossed the equator before, and are thus the lowest form of sea life), and the shellbacks (the veterans of previous equator-crossing). Franklin Delano Roosevelt himself had a certificate testifying to his having crossed the equator back in November, 1936.

As they cross the equator, the pollywogs are summoned - sometimes at the behest of “Davy Jones’ - to the court of King Neptune, who occasionally has maidens. The pollywogs are then initiated into the ranks of the shellbacks, by way of various embarrassing tasks: being doused in sea water, getting locked in stocks and pillories, etc. The pollywogs sometimes have to “kiss the baby,’ which just so happens to be the belly of the ship’s most obese man.

Most sailors were happy to break up the ocean’s monotony with good, bizarre fun. Sadly, these initiation ceremonies - especially in the armed forces - allowed ample opportunity for abuse: some crews took the opportunity to dole out full-blown beatings, which lead to the well-deserved suspension or scaling-back of the ritual. But many tourist vessels still observe it: they’re happy just to dump salt water on peoples’ heads, and dress in silly costumes.