The Iowa class ships were built for many things. One big reasson they were built was to take on the Yamato class battleships with their 18.1 inch guns. Japan built two of them plus had a third hull that was converted to a flattop. The flattop was sunk by a sub while it was moving from where it was built to where it was to be armed. Poor guy looking thru the periscope could not figure out what it was. It did not show up in any of their silhouette books. (it was the first flattop on that hull ever made!). Captain decided, what the heck, it's theirs and it ain't friendly, so he sank it.