Single Mission - 668I

So I having a little trouble with one of the single missions in 688I. It is #5 , I believe, but dont quote me on that. You are tasked to track a Russian renegade Delta boomer(SSBN). So I have played this scenario three times and I have yet to find this so called delta, or even the Akula for that matter. I get the Victor II all day and can track him for hours, but I never seem to find to find the Delta or Akula.

I have even resorted to driving through his area of constrant at high speeds last night making noise and still I got nothing. Oddly enough he never detected me either. I know boomers are supposed to be quiet as I was on a few but undetectable is a little far fetched.

Any advice?