rock the boat vs unsettle

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. 

unsettle

verb
  • To bring into disorder or disarray 

  • To make upset or uncomfortable 

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