Many years ago, I went with a friend who had just graduated from submarine school to some event at Philadelphia's Navy Yard. We got out of his car and in front of me was what looked like an immense wall. I figured it was some sort of warehouse, said as much and asked where the entrance was. My friend looked at me and smiled. "Frank, that's an aircraft carrier." I replied, "You mean that floats?" He told me to look up , and sure enough, way, way up, was the bridge. They really are big.