I had successfully torpedoed a battlecruiser, but was stuck under a destroyer until the battery charge was almost gone. Since you only live once, I decided to surface and try a daring gun attack. Caught them so by surprise that my gun crew badly mauled them before they noticed and fired back. This shot is the first instant of that.
My next shot sank them - the one you see flying my way crippled my deck gun but I got under again before anything worse happened.