Google is your friend.
See... http://www.history.navy.mil/faqs/faq92-1.htm
...and...
"There was one final ceremony on board both icebreakers as they sailed south. As they had not celebrated the crossing of the Artic Circle on their way to battle the Germans, there were still a number of "ice worms" on board. These were the unfortunate individuals who had not been initiated into the realm of King Boreas, as all sailors who cross into his territory must be, and made into "Polar Bears," complete with a certificate. More than 300 Coast Guardsmen, who experienced battle in the icy north, put up with the tortures inflicted by the current members of the crew who were already Polar Bears, and they too joined the hallowed ranks of Arctic veterans."
http://www.uscg.mil/hq/g-cp/history/Externsteine.html
Great! Came up at lunch today -- the autumnal equinox. King Boreas?