drop out vs rock the boat

drop out

verb
  • To be lost or momentarily interrupted. 

  • To leave (school, a race, etc.) prematurely and voluntarily. 

  • Used other than figuratively or idiomatically: see drop, out. 

  • To opt out of conventional society. 

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 drop out and rock the boat occurred in a corpus of books? (source: Google Ngram Viewer )