Hello Ping,
Oh no, I was not there. I have limited experience in submarines, mostly at Disneyworld´s "20.000 leagues under the sea"
But I am following the Soviet involvment in the 1982 South Atlantic War, and I am somewhat puzzled about the lack of official "knowledge" about soviet submarines in the area.
For example, declass CIA´s "Soviet Naval Deployment Outside Home Waters 1982" does not mentions K-513 or the F-class down south.
Other sources claims that a Soviet sub was "probably" there, but no further info was released. Soviet sources are also vague.
Regards!