We had a FV cabin on Century on deck 8 and never noticed any vibration whatsoever. On Mercury, we happened to be in the Spa pool area when we were pulling away from the dock and thought the ship was breaking apart the vibrations were so bad. The sliding glass doors were banging in their frames so hard I thought they would break. That said, we never after that felt any vibrations in our cabin which was mid-ship or at dinner in the restaurant. We were on the deck more than once pulling away from the docks in Alaska and never felt those severe vibrations again.