frame of reference.

"Crossing the Line is nearly as old as seafaring itself; even in antiquity sailors engaged in rituals when crossing certain parallels. Our modern practice is believed to have evolved from Viking rituals, executed upon crossing the 30th parallel, a tradition that they passed on to the Anglo-Saxons and Normans in Britain. Many other cultures had some sort of rite, religious or otherwise, upon passing an important landmark at sea. The Phoenicians, for example, gave sacrifices to their sea god upon passing the “Pillars of Hercules” (today’s Straits of Gibraltar). Later, similar rites evolved in other countries for passing the Tropic of Cancer and the Tropic of Capricorn. Today, a myriad of different certificates (and often ceremonies to accompany them) commemorate other passages.

Early Crossing the Lines had a fairly serious purpose, however: they were designed to test the novices in the crew to see whether they could endure their first cruise at sea. Ceremonies in the seventeenth century were particularly rough. Today, Crossing the Line no longer has such serious undertones, although some of the novice/veteran dichotomy persists in the titles given to those who have and have not been initiated by the rite: those who have crossed the equator are termed “shellbacks” (often called “trusty shellbacks”) and those who have not are called “pollywogs” (also rendered “polliwog”).

What does a crossing the line ceremony entail? Traditionally, the night before King Neptune (the most senior shellback) sends a messenger informing the Captain that he intends to board the ship the following day, and summoning a list of slimy wogs to appear before him. The actual ceremony revolves around the pretext of “preparing” the wogs for their audience before King Neptune. At this meeting, King Neptune appears with his entire retinue, Queen Amphitrite, and Davy Jones and officially proclaims the wogs to be trusty shellbacks."

credit: goatlocker.org; gudungisengblog.blogspot.com