Did PC-522 sink U-381 15 May 1943?
According to Edwin P. Hoyt's "U-Boats Offshore" (.p.253)
PC-522 exploded depth charges against a contact 15 May 1943.
The explosion could be heard 7 miles away!
The U-boat.net lists U-381 Missing between 9 May-21 May 1943
(Have tried to get in touch with U-Boat net but so far no luck)