I am currently sailing on the new inland container ship and I am wondering why the ship rocks so much when you are moored at the quay. I am a ship's captain for a shipping company and I sail a 300 ton passenger ship and the ship doesn't even rock when there is a wind force of 6 and a bit of waves. The ships don't just rock when there is a little wind force, as soon as you move the rudder a little the ship also starts to rock and when sailing on a straight stretch the ship just rolls from front to back.