Hello Brian,

According to the book, this refers to the counter-attack following the sinking of CARLO DEL GRECO and FABIO FILZI. The patrol report is silent as far as damage sustained. It does mention that 48 depth-charges were dropped but does not state if they were close. The destroyers may have dropped depth-charges as a deterrent. They were quite busy recovering some 400 survivors. Although it is quite possible that the submarine suffered some damage, it did not appear to impair its fighting capacities. Her radio appeared at least to have been able to receive signals: she did receive one from S.10 the following evening. She seems to have stayed in the area following S.10 orders and not because of any crippling damage.
If damage was incurred, she returned from patrol on 18.12.41 and sailed again on 1.1.42 which does not indicate very serious problems. BTW I think "The Fighting Tenth" is an excellent book. Of course recollections some time lead to embellishments but I think this happens to all of us.

Best regards,

Platon