kayak vs rowboat

kayak

noun
  • A type of small boat, covered over by a surface deck, powered by the occupant or occupants using a double-bladed paddle in a sitting position, from a hole in the surface deck 

verb
  • To use a kayak, to travel or race in a kayak. 

  • To traverse (a body of water) by kayak. 

rowboat

noun
  • A small open boat propelled by oars (by rowing). 

verb
  • To row a boat of this kind. 

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