boathook vs setting pole

boathook

noun
  • A hook attached to a pole used for pulling or pushing boats, rafts, logs or other objects to or from the side of a boat. 

  • A pole or rod with such a hook at one end. 

setting pole

noun
  • A pole, often iron-pointed, used for pushing boats along in shallow water. 

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