Need Re-Teaching

Okay so coming from SH3 and using half manual targeting, its been about a year and I need a lesson again. Im doing Trevally tutorials on RAOBF and 90 Degree shots (That was my signature, I dont mess with those angular shots unless I absolutely NEED to)

Basically I need re taught on how to intercept targets, mainly Hydrophone contacts, what I did is I took to marks at abour 3 hours apart of what direction my contact was then I connected those marks to get his approximate heading, I try to surface and beat him to a spot and no dice. So yeah, anyone want to school me again so I can feel good about sinking some tonnage?

Casey