The line-crossing ceremony is an initiation rite that commemorates a person's first crossing of the Equator. The tradition may have originated with ceremonies when passing headlands, and become a "folly" sanctioned as a boost to morale, or have been created as a test for seasoned sailors to ensure their new shipmates were capable of handling long rough times at sea. Equator-crossing ceremonies, typically featuring King Neptune, are common in the navy and 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.