"Sea Dog" resumed her patrol to the southward. That night, she took up station to the north of Nyudozaki and, at 0635 on 12 June, sighted a small convoy as it rounded that headland and continued northward, through relatively shallow waters, toward Henashi Zaki. "Sea Dog" fired on the freighter farthest from the coast. "Shinson Maru" broke in two and sank in about two minutes. Her companions moved even closer to the coast. "Sea Dog" headed for deeper water and patrolled to the southwest.