SECRET.
 
   
  REPORT OF ATTACK ON U-BOAT.           Continued.
     
  Item 20. NARRATIVE.  
     
  10.  . . . . . . . . or so severely damaged that she could no longer be a menace to the approaching convoy.  
     
  11.  As far as could be seen there was nothing outstanding in appearance of the U-Boat, it being a normal 570 ton type painted a dark colour.