大隅諸島
Sailing with , she stopped off at Midway Atoll on 12 June, glanced off a whale on 15 June, and on 22 June, transited Tokara Strait to enter the East China Sea. On 23 June, she and "Tang" took up stations in the Ōsumi Islands, an island group to the south of Kyūshū. That afternoon, "Sealion" unsuccessfully conducted her first attack, then underwent her first depth charging.