That's the pits, have had the same type experience and yes it is frustrating

From 800 yard a little AoB error won't matter much, no doubt speed est. or she saw the periscope. Either way I feel your pain.
CVs and BBs are hard to come by unless you go looking for them and know where they are supposed to be. I haven't gotten too many myself.
Last one I got jumped ME. Coming out of the Flores sea at 23 knots head on. Some how the DDs missed me and I had just enough time to get a quick guesstimate and get all 4 fish off (Porpoise class). A down the throat shot. 2 hits and the other 2 didn't have time to arm. She went down thou.
One of the most exciting experiences in all of Sh4 and it was over in a matter of one or two minutes.
Magic