I played 4 DiD careers, each about 9 patrols as simulated with SH 3 comm...
The first one was an Atlantic campaign starting in late 1942 and ending early in 1944 when I was assigned to a training fleet...
The second one was a type XXIII career from Jan 1945. I got sunk on the first patrol by an aircraft while recharging the batteries via Snorkel... Radar detector attached to it warned me when the airplane was just 1,2 km far...
The third one was a Black sea campaign, after 11th patrol I was retired...
And the fourth one is a Med campaign starting in mid 1941... And In mid 1942 after 6 patrols, I am still alive...