The Y and CL are constantly coming out of the Bungo heading down the coast of Kyushu in late war...more so after it's mid-April 45 suicide run. 5 or 6 Mk16's that are available then will take it down.
I always seem to catch it at night with moderate to heavy seas and fire 6 forward tubes from about 6,000 or 7,000 yards. But like anything, once you know where it is and you catch it so many times it becomes routine to the point of boring.