Here you see one of IJN Mutsu's 41cm (That's right 41. That's 16.1 inches for you imperialists. The biggest railway artillery piece was the Gustav 80cm) twin gun turrets. When returning to port one of her magazines exploded and split the ship in half, killing most of the people on the ship. Later recovery operations brought up most of the ship. You can dive to the wreck or what's left of it.