You may be right, however, I'm having a hard time imagining the crew not hearing/feeling the "bump in the road". Also, the holes/tears were in the aft of the ship. Unless the aft was somewhat lower in the water than the fore, I would have thought the holes would be more forward, if your theory were correct. Any "old-salts" out there have any insight?
I wondered about the noise factor as well. However I am no expert there. When you have something as heavy as that ship being hit by such a narrow band...then I don't know if you would hear it. Kind of like if you have a VW bug and rock hits the side of it then you know you have been hit. But if you are driving a semi and rock hits the side of your trailer then you may never know it. I imagine a ship that large and heavy has a lot of back ground noise as it is. Would you hear this if an object cut the hull like a knife? I really don't know.