On 14 May, "Bonefish" approached a convoy of three tankers and three escorting destroyers, steaming off Tawitawi in the Philippines and headed for Sibutu Passage. The submarine fired five torpedoes. One hit under the bridge of a tanker and another struck under the stack, enveloping the ship in smoke and flames. The destroyers converged on "Bonefish" for counterattack, but she escaped into the depths. Postwar records show that, while her torpedoes only damaged the tanker, they sank one of the escorting destroyers, "Inazuma", which was known for having rescued 376 survivors from and 151 from during the Second Battle of the Java Sea.