Hehe funny thing,just run into my first convoy in SH3/GWX career in sector BE56(5th patrol).
After we managed to sneak pass the escort(thanks Brag for guide on your site) i surfaced right in middle of it, and there it was HMS Nelson and following her, big, fat tanker, coming to straight in front of me

.I sent off all 4 torpedoes(3 in tanker, 1 in Nelson) and dived to 140m.
Got confirmation for 2 impacts and 1 ship sinking,(found out later it was tanker).I assumed that i missed Nelson.
After almost 2 hours of playing "seek and hide" with what i believed was 2 escorts, we surfaced 9 km away, undamaged.On my shock ,behind me was Nelson, 8 km away and not moving.
It looks like she was one of my chasers, but got ripped her belly open by one of my torpedoes earlier and after flooded came to full spot, sinking slowly.

It took her awhile to sink after that.
Needless to say , now i am hooked to this game.