The tradition may have originated with ceremonies testing seasoned sailors to ensure their new shipmates were capable of handling long rough times at sea. Sailors who have already crossed the Equator are nicknamed (Trusty/Honorable) Shellbacks, often referred to as Sons of Neptune; those who have not are nicknamed (Slimy) Pollywogs (in 1832 the nickname griffins was noted.
Equator-crossing ceremonies, typically featuring King Neptune, are also sometimes carried out for passengers’ entertainment on civilian ocean liners and cruise ships. They are also performed in the merchant navy and aboard sail training ships.
