No no no,you misunderstand me

You are talking about a 90 degree parallel shot while moving with your target,I am pretty much a master at this now,at least I feel very confident with these shots (using steam torpedoes that is).I am talking about shooting while FACING (facing perpendicular at 90deg to his course) your target from a dead stop.So,If I was at 1000m,and I was using an ETorp,waiting for a firing angle of 10deg in the scope would no doubt be too late,yet firing on say 20-25deg in the scope would give a better lead on the target with more time to hit it.
Ultimately,I desire info on the optimal TIME to release the torpedo,because if the release is too late it passes harmlessly across his stern,as happened to me earlier tonight.
This info would also greatly benefit those trying to shoot at extreme range and beyond.
Do you understand what I mean now?