USS PC-823, a 173-foot submarine chaser, was built at Sturgeon Bay, Wisconsin. Commissioned in July 1944, she served in the western Atlantic during World War II, being assigned to air-sea rescue duties during at least some of that time. PC-823 was decommissioned in February 1946 and transferred to the U.S. Merchant Marine Academy for use as a training ship, apparently receiving the name Ensign Whitehead. She was stricken from the Navy List in June 1948.

In 1949, the personnel of the Republic of Korea Navy donated funds to obtain their service's first significant warship. The former PC-823 was purchased and renamed Pak Tu San (Korean Navy # PC-701). Provided with weapons by the U.S. Government, she arrived in South Korea shortly before the June 1950 outbreak of the Korean War. Pak Tu San remained in ROK Navy service until 1960.