Idiom
don't rock the boat
do not upset people by trying to change a situation.You shouldn't sit there and say everything's fine, don't rock the boat.
Usage notes: sometimes used without don't:
Of course you'll want to rock the boat.
To my mind, "make waves" & "rock the boat" are not syns, tho closely related, as rock the boat cannot be used to describe the creation of a new situation, whereas make waves can--SL, 9/02
Related vocabulary: keep your nose clean, make waves