It is hard to know exactly what was the crush depth of those subs, at first it was a war secret, and after the war not too much info about that.
But at siome web pages is presented information about situations where they dive too deep and return.
Even with the design data, it is realative, because the hull suffer stress, and the crush depth sure will vary with the hull life time.
SH3 Dev. Team confused the maximun operative depth with the crush depth.
The maximun oparative depth was intended to ensure a good hull life time, but the maximun opartive depth not means the hull must crush at that depth.
In example if a hull with maximun oparative depth of 225m is used so never go down that value, in example it will have 2000 dives life time prior to have stress problems, intead if it dive frecuently to 300m, its life time may be reduced in example from 2000 dives down to 500 dives. (this values are only suposed examples, not real values)
In some places i remember to read, they ensure the crush depth was near to double of the max operative depth.
In example here... look at "The Boats" and then look at VII C/42 :
http://www.dataphone.se/~ms/ubootw/welcom.htm
I remember some times people mentioning historytells about determined sub which dives too much beyond the maximun operative depth and back home.
May be some body can remember any one.
This was a long discusion on SH2 and at early times in SH3, you can take the crush depths stored as data into the SH3 Crush Depth Mod from TimeTraveller as a good value.
Hope this can help you...
