flatboat vs rowboat

flatboat

noun
  • A boxy, flat-bottomed boat used for carrying livestock, freight, and people on rivers. 

rowboat

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

verb
  • To row a boat of this kind. 

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