Celebrated as one of the US Navy's finest rituals is the Shellback, an initiation for first-timers crossing the equator. More formally, the "line-crossing ceremony," where Pollywogs become Shellbacks, pay tribute to King Neptune, the God of Sea. Some element of pain, I've been informed, is involved. The owner of this license plate, seen in Murfreesboro, Tennessee, served aboard the USS Mahlon S. Tisdale, a guided-missile frigate.