Are Japanese destoyers too good at detecting your sub??

Originally Posted by Galanti

No, but in my experience, and please correct me if i'm wrong, pinging destroyers mean that they suspect there's a snake in the grass, and are taking appropriate measures.

Which unfortunately means the convoy or TF they're escorting is taking evasive action (ziggzagging and increased speed) and your attack has been effectively foiled.

your reasoning is sound but it doesnt work that way in the game. the game has them pinging away 24/7 (unless they are listening) so that by itself means nothing as to weather or not you are detected just as RR said. you just need to set up your angle of attack to avoid a profile that increases your chances of being detected.