After a short visit to Sasebo between 16 and 20 April, "Bataan" resumed her alternating patrols with HMS "Theseus" off the west coast of Korea. On 21 April, in an unusual incident, two Corsairs of VMF-312 were attacked by four Russian-made Yakovlev Type 3U Yak fighters near Chinnampo. Marine Corps Capt. Philip C. DeLong shot down two of the Yaks, and heavily damaged a third, while 1st Lt. Harold D. Daigh, USMCR, shot down the fourth. According to Capt. DeLong, the North Korean pilots "were considerably inferior in flying ability to the Japanese of World War II."