watercraft vs wherry

watercraft

noun
  • Any vessel with implements designed to move it in arbitrary direction through one or various bodies of water – a boat, ship, sea scooter, or similar vehicle. 

  • Skill in boating, swimming, or other water-related sports. 

wherry

noun
  • A light ship used to navigate inland waterways. 

  • A flat-bottomed vessel once employed by British merchants, notably in East Anglia, sometimes converted into pleasure boats. 

  • A liquor made from the pulp of crab apples after the verjuice is extracted. 

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