Our nuclear submarines would probably be easily tracked with their "listening network" (I don't know anything about it) but diesel-electric submarines, which seem to be making a resurgence although not with the pro-nuclear forces in the navy, are far quieter and harder to detect. Combine that with the sound matting being develop for next gen subs and/or titanium hulls like Russia used to make, and you've got a very formidable submarine capable of high speed travel which will be very hard to detect with passive or active sonar.