'Caulkhead' is a name taken proudly by born-and-bred Isle of Wighters. One cannot, so far as I can tell, become a caulkhead just by moving to the Isle; it would help to be of tenth-generation smuggler stock, follow pagan rites, and be able to strip raw fish to the bone with one's needle-like teeth. The etymology of the term is uncertain. It quite possibly derives from 'caulk' (thanks ascorbic), which if true, presents an interesting (if unsurprising) indictment of the denizens of Wight.