Last time I checked with my mates in the submariner corps, diesels were still quieter than nuclear boats, the difference is the underwater endurance, ie the diesels have to snorkel to run the engines and re-charge batteries. So it comes down to who has the greater endurance, the sub or the surface fleet, can the sub float away quietly in the current - under an inversion layer - before the surface fleet with their drones pull up stumps?? Just slightly off topic here btw