The Germans walked away from the maintenance contract on those subs due to non-payment.
The Argentines kept them operational by cannibalizing 4 other partially completed subs.
I watched a documentary about USS Kentucky, a missile boat of ours.
As soon as they submerge to a certain depth, they stop the boat and do a stem to stern inspection looking for leaks.
These are the most advanced undersea craft available, and even the US Navy leak checks their boats.
That is respect for the elements for you. I was very impressed.