Forum:Why didn't WB raise the ice above the encircling wall?

So I was just thinking about how rediculously powerful WB is/was and how extreme his manipulation of the Earth and sea was, so it just occured to me why was he not able to simply raise the area that the pirates were standing on (yes I know it was ice covered water, but there was still land below that) over the encircling wall, or pull the rest of Marine HQ lower into the sea in effect lowing the encircling wall in the process?