[Corsair]

I find 75% of my targets through routine hydrophone checks around 20m deep, all stopped and myself behind the wheel. I don't count the times when I picked up sound contacts and going back to the command room and asking for a report my sonarman would reply "no sound contact". By good weather you can find them at very long distance... I go for a straight bearing first, then checking every 5/10 mns I get an idea if it is moving left or right of me and adjust my bearing always some degrees ahead. After that it's up to you to decide if you just wait for him when you think you are on its path, or surface and speed up to catch up... depends if it's day or night, if plane threat or not, etc... Since they don't just go circling around, depending where you are, you can also figure out what their destination is or the other way around where they come from... they have a logical route.
If you check in the community online manual, there is I think a link to a nice tutorial called "The Hunt" which helped me in the beginning.