"Springer", , and sailed on 20 April for the Yellow Sea where they were to operate as a wolfpack. Eight days later, the pack checked Tomei Harbor on Fukue Shima. At 05:15, "Springer" sighted two ships hugging the coastline, but she found it impossible to close nearer than . She heard 14 explosions at approximately 06:30. "Trepang" had sunk "Transport No. 146" and was being depth charged by the victim's escort. "Springer" headed out of the harbor, and sighted the escort returning alone. At 08:30, the submarine launched three torpedoes. The target went dead in the water; and, as the crew was abandoning ship, "Springer" fired another torpedo. It hit under the target's No. 1 turret and blew off her bow. Two planes and two patrol craft approached, so "Springer" went deep and cleared the area, leaving Japan's "Submarine Chaser No. 17" to sink.