Post-war examination of "Kriegsmarine" records indicate that the submarine first attacked by the Mariner may have been , though that boat's logs do not record the attack. It is possible that the attack went unnoticed by the boat; of the three depth charges and one 100-pound bomb that were dropped, one depth charge was a confirmed dud, one was dropped too low to arm, and neither the third depth charge nor the bomb were seen to explode. After the attack, the Mariner searched the area for 20 minutes, but saw no explosions, bubbles, or debris.