I did sink a Kongo BB in my first patrol with an old S lady, I was based on manila and was sent to patrol whatever is the name of the strait or pass up north of Aparri, then a task force came right to me, just waited, maneuvered when IDed the ships, picked my target, waited again and fired. 4 hits and she went to hell. I was lucky tho, the escorts went to check something and left the BB's all alone. There I got the hhang of the PK, now I can handle it more decently at 100% realism.
Also there is a lot of task force traffic early in the war traveling from Formosa - I think - to Singapore.