defy vs rock the boat

defy

verb
  • To challenge (someone) or brave (a hazard or opposition). 

  • To refuse to obey. 

  • To not conform to or follow a pattern, set of rules or expectations. 

rock the boat

verb
  • To disturb the status quo or go against rules or conventions, as in an effort to get attention. 

  • I'd just jump in and fix it, but that's not my job, and I don't want to rock the boat. 

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