SUBSIM Radio Room Forums - Some important data i need

I will ask some question as below
1\ How deep and lang of the sonar of japanese Destroyer ? in other words , what depth for us is safe ? Yeah! The Dstroyer is always head-turning left and right regular in order to enlarge their detection range.So Who can tell me their head-turning angle. I think this data is very important.
2 \When I counter a fleet. For example four Destroyer around one passenger line ship . Yeah they consist a triangle similar as about thequilateral triangle in ideal. How can I attack the passanger line ship undetected ?

If you can tell me something helpful ,Thanks in advance!