Germany makes some very quiet diesel electric subs that they export to other countries. Type 209 submarine - WikipediaGive me one ping only Vasily .....
I read somewhere that one of the real threats are fairly economical and extremely quiet diesel-electric subs intended to operate in and around coasts not out in the deep blue. The North Koreans have some and they are very, very quiet. Don't know how that rates in 2019 any more.