skeg vs tailfin

skeg

noun
  • A fin-like structure to the rear of the keel of a vessel that supports the rudder and protects a propeller. 

  • A surfer; a person who leads a surfing lifestyle. 

  • A look or glance. 

  • A similar construction on a boat that acts as a keel. 

  • A fin that serves to stabilize a surfboard. 

tailfin

noun
  • A fin on the tail of an aircraft, vertical stabilizer 

  • A fin at the tail of a fish, caudal fin 

  • A fin-like projection at the rear of a car, common on American cars of the 1950s. 

How often have the words skeg and tailfin occurred in a corpus of books? (source: Google Ngram Viewer )