forecastle vs gunwale

forecastle

noun
  • A raised part of the upper deck at the front of a ship. 

  • Crew's quarters located at the forward part of a ship. 

gunwale

noun
  • The top edge of the hull of a nautical vessel, where it meets the deck. 

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