And, apparently, the ship isn't even moving sideways. Weird, but I believe this guy - he's apparently something of an expert in the field. Facts
I think I like the story better if the ship moves. But then you'd have to think that if it did, everything in that ship would be flying around every time they fired a broadside, and what practical purpose would that serve?
One other interesting fact I ran across checking this out: the turrets in the Iowa class
aren't even attached to the ship. They rest on rollers, and if the ship turns over the turrets will fall out.