The months of November and December 1943 and January 1944 found "Saufley" performing escort duties for the reinforcement of Bougainville. In February, "Saufley" was engaged in the assault on the Green Islands which broke the Japanese Rabaul-Buka supply line and provided the Allies with another airfield near Rabaul. Antisubmarine patrols were followed by call fire support missions during the occupation of Emirau Island. This action, which completed the "ring around Rabaul", took "Saufley" into April. She had returned to the Emirau-Mussau area when, on the morning of 7 April, she gained contact on a submerged submarine. Forty-five minutes and 18 depth charges later, two underwater explosions were heard. Within hours, oil covered the area. Postwar review of Japanese records identified the sunken submarine as the Type J1 submarine . Following escort duties to the Admiralties, "Saufley" returned to Purvis Bay on 18 April whence she conducted exercises with TF 38 into May.