According to Tommy Makem, on one of his PBS specials said that it is based on the experience of a man named Scoggins, I believe. Supposedly, he wrote an article about his whaling experience. The article was later read by Ken Graydon, who wrote the song we now know as The Whaler's Tale. Makem also noted that there is a place in Baja California named after Scoggins.

Hope this helps. Robby