coracle vs logboat

coracle

noun
  • A small circular or oblong boat made of wickerwork and made watertight with hides or pitch, propelled and steered with a single paddle and light enough to be carried on a person's back. 

logboat

noun
  • A dugout canoe 

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