Originally Posted by Sailor Steve

And you would lose that bet. A battleship is armed with 'secondary' batteries specifically to protect them from destroyers and the like. They have a very limited amount of large shells, and they didn't waste them on small targets. An Iowa class battleship could fire the 16" guns at a rate of about two per minute, and they carried 20 5" guns that could fire about 10 shells per minute, would be just as effective against a small target and a whole lot cheaper. It would be like your u-boat shooting at a guy swimming in the water with your deck gun.

There was one exception - USS Iowa and New Jersey tried to sink the Japanese destroyer Nowaki with their 16" guns, but the range was in excess of 35,000 yards, far outside the range of the 5" guns. Also, they didn't score a single hit.