Early on 3 April, an enemy bomber forced her to dive, and she ran submerged for the remainder of the day. That evening, she surfaced once again and soon made radar contact with a good-sized target. The fact the enemy ship carried radar, coupled with the appearance of a second target larger than the first, indicated she was some type of warship escorting a merchantman. Darkness and fog dictated a surface attack. "Tench"’s report claims the target, the large cargoman, took one torpedo hit and erupted in a splendid pyrotechnic display. Unfortunately, there is no evidence to confirm the kill.