Man there are alot on uninformed opinions in this thread. I wasn't navy either,
but I know submerged boomers don't use radar. There is also a big difference between
active sonar and keeping a listening watch. You don't have to generate sound to hear
another vessel's self generated noises. Reactors and screws make noise all by themselves.
Traditionally missile subs have had some of the best sonar crews in the navy as the whole
point is to hear the other guy before he hears you. The problem is that both subs are designed
to be very quiet, so they may not have been aware of each other's location.