Marines have long been known as Leathernecks. This nickname comes from the leather collars that Marines used to wear in the early days of the "Fighting Tops". Legend has it that these high collars were worn to protect the neck and throat from saber slashes. The high collar of the modern Dress Blues pays homage to those Marines of old. I happen to be a Marine, and thus a "Leatherneck."

Furthermore, my specific MOS deals with Assault Amphibian Vehicles, AAVs, or AmTracs (amphibian tractors). The first, designed and manufactured prior to world war II by Donald Roebling to be used as a search and rescue vehicle in the Florida Everglades, was known as the Roebling Alligator. Drafted into service by the Navy and Marine team during WWII the alligator, now known as LVT (landing vehicle, tracked) was instrumental in the Island Hopping campaign leading up to the invasion of mainland japan. LVTs (now known as AAVs) have evolved a great deal since then, but those of us who crew and wrench on them had been known as Alligator Marines since.

Hence GatorNeck.