在朝鮮アメリカ陸軍司令部軍政庁
The Republic of Korea Navy was established as the Marine Defense Group on November 11, 1945. In June 1946, the Marine Defense Group became the Korean Coast Guard, and officially recognized by the United States Army Military Government in Korea. The Korean Coast Guard acquired 36 patrol craft (mainly ex-IJN and USN minecraft) through the Military Government. In October 1949, the ROK Navy purchased a 600-ton submarine chaser, the former USS "PC-823", which was renamed as ROKS "Baekdusan" (PC 701) and became "the first significant warship of the newly independent nation". The Navy purchased three additional "PC-461"-class submarine chasers before the Korean War, which began on 25 June 1950 when North Korea invaded South Korea.