The literal meaning of this phrase is when you do something to make a boat move from side to side, which would cause it to rock, often in a negative sense, as it could throw anyone on the boat, into the water!
The idiom derives from the above literal meaning. In a sense, the idiom means to cause trouble where it is not welcome. Causing trouble, or doing/saying something where it would only disturb a situation, that is otherwise satisfactory as it is.
Example sentences:
“Everything is fine here, we don’t need you to rock the boat!”
“The substitute teacher tried to change some of or processes while she was here and has managed to rock the boat quite hard. We need to revert those processes to the way they were before!”
“The media will definitely try to rock the boat just before Election Day, I’m sure of it.”
