Republic of Korea Navy
By Edward J. Marolda
Perhaps the most aggressive and effective, if smallest, member of the South Korean armed services during the first year of the Korean War was the Republic of Korea Navy (ROKN). At the outset of the conflict, the 6,956-man ROKN, with 71 naval vessels of various types, was outnumbered by the 13,700 men and 110 naval vessels of the North Korean navy. The concentration of ROKN units at western and southern ports on June 25th enabled the Communists to land ground forces at a few locations along the east coast as far south as Samchok and send a 1,000-ton freighter loaded with 600 troops toward the port of Pusan.
The ROKN and its UN allies, however, soon drove not only enemy combatants but reinforcement and resupply vessels from the seas that touch the shores of the Republic of Korea. The first night of the war, submarine chaser PC 701 sortied from Pusan, made contact with the North Korean freighter, and sank her. The enemy ship's embarked troops would no longer pose a threat to the vital port of Pusan. On July 2d, just south of the 38th parallel in the Sea of Japan, U.S. cruiser Juneau, British cruiser Jamaica, and British frigate Black Swan sank three torpedo boats and two motor gunboats of the North Korean navy. This was the first and last time during the war that enemy naval forces elected to fight the UN navies for control of the sea.
Also on July 2d, the ROKN's Naval Base Detachment at Pohang wiped out a North Korean landing force. The following day minesweeper YMS 513 destroyed three Communist supply vessels near Chulpo on the southwestern coast.
Despite these initial successes, the result of action by brave and resourceful local naval commanders, the ROKN suffered from lack of central direction in the early weeks of the war. This was due to the absence of the ROKN Chief of Naval Operations, Admiral Sohn Won Il, who was in the United States to take delivery of three former U.S. Navy submarine chasers, and the capture by the North Korean People's Army (NKPA) of the ROKN naval headquarters in Seoul. Consequently, Commander Naval Forces, Far East, American Vice Admiral C. Turner Joy, with the consent of South Korean authorities, designated Commander Michael J. Luosey as Deputy Commander, Naval Forces, Far East, and directed him to take operational control of the ROKN. With an American staff of one other officer and five enlisted sailors, the young officer assumed operational control of the ROKN at Pusan on July 9th. The other navies of the UN coalition also followed the operational direction of the U.S. Navy during the Korean War. Luosey spent the first few weeks coordinating with the other UN forces and arranging for logistic support of his ships and men. He also set up inshore patrol sectors along the coasts of South Korea and directed the ROKN's one tank landing ship (LST) to move a 600-man force of South Korean marines to Kunsan on the southwestern coast. The small contingent was unable to stop the onrushing NKPA, so a few days later the marines were reembarked. During the next two weeks, the ROKN used the naval infantry in short-duration landing operations in the same area.
The tide began to turn as Admiral Sohn reached South Korea with the newly acquired submarine chasers and the ROKN helped take the steam out of the enemy's offensive push toward Pusan. On July 22nd, YMS 513 destroyed a trio of Communist supply vessels near Chulpo. Less than a week later, PC 702 and PC 703 caught a group of enemy sampans carrying ammunition west of Inchon and sank twelve of them.
There was no respite for the ROKN as the enemy's efforts to crush UN ground forces holding the Pusan Perimeter approached a climax in August. With the allied air forces making travel on the highways of South Korea increasingly lethal for enemy logistic units, the Communists looked to the sea to ease their supply and reinforcement problems.
On the west coast during the first week of August, YMS 302 and other ROKN vessels eliminated motor and sail boats and junks carrying supplies. Five times during the period from August 13th to the 20th, the ROKN made contact with Communist vessels, on one occasion sinking fifteen of them and capturing another thirty. PC 702 and four motor minesweepers sank numerous enemy craft, drowning their embarked troops, and seized many more. To extend the ROKN's reach further north along the west coast, on August 9th the LST established an advanced logistic support base on Ochong Island near Kunsan. During this same period, the ROKN disrupted a North Korean effort to capture Pohang with troops landed by sea. The ROKN played an important, if small part in the overall UN effort that defeated the North Korean attempt to crush the Pusan Perimeter and push the allies into the sea.
Like other UN forces, the ROKN carried out operations during late August and early September to prepare the way for the amphibious assault against Inchon, Operation Chromite, which would change the course of the war, on land and at sea. Understanding the ability of naval forces to range far and wide on the enemy's flanks, Commander Luosey directed the ROKN to occupy islands on Korea's Yellow Sea coast to divert enemy attention from the impending amphibious assault and to use them as bases of operation for gathering intelligence, landing guerrilla parties, and conducting coastal raids. On August 17th and 18th, in Operation Lee, named for the commanding officer of PC 702, that submarine chaser and two minesweepers landed a 110-man guerrilla force on Tokchok Island southwest of Inchon. The following day, men were landed on Yonghong Island in the approaches to port. Then, on September 8th, to divert the enemy's attention from Inchon, Lee's units landed guerrillas on another island to the north.
In this period, the allies discovered that the North Koreans were laying sea mines in the approaches to the western coast. Confirming this worrisome development, on September 10th PC 703 sank a Communist minelaying vessel off Haeju. Even though allied warships spotted and destroyed other enemy mines as they steamed toward Inchon on September 13th and 14th to inaugurate Operation Chromite, the fearsome weapons did not prevent accomplishment of the amphibious assault. Soon, allied ground forces captured Seoul, ended the siege of Pusan, and forced the badly bloodied NKPA to flee to North Korea. Simultaneously, the ROKN recaptured islands in the south lost earlier to the enemy, took control of other islands off North Korea, and established forward bases at Chinnampo on the west coast and Changjon on the east coast.
As UN ground forces, supported by air forces, pursued the enemy and occupied almost all of North Korea during October and November, Communist mines exacted revenge by sinking and damaging allied naval vessels. Sea mines manufactured in the Soviet Union and deployed under the direction of Russian advisors in the waters off the Korean Peninsula took their first victims in late September. On the 26th, a mine severely damaged U.S. destroyer Brush and killed and wounded 47 of her crew in North Korean waters. During the next week, mines sank or damaged three other UN ships, including YMS 509.
Mines not only prevented the 250 ships of the allied naval task force from landing troops of the U.S. X Corps and the South Korean I Corps at Wonsan in mid-October, but they sank and damaged UN ships and killed and wounded many sailors. On September 12, while clearing lanes through the 3,000 mines laid in the approaches to Wonsan, U.S. minesweepers Pirate and Pledge hit mines and quickly sank, with great loss of life. Six days later, ROKN YMS 516 virtually disappeared from the explosion of an influence mine. Half of the minesweeper's crew went down with her.
The allies fared better in the clearance of the western port of Chinnampo between October 28th and November 6th. Involved in that operation were 10 U.S. ships, 13 Japanese-manned minesweepers, and ROKN YMSs 502, 306, 513, and 503. To assure that the approach lane was free of the over 300 mines laid by the enemy, on November 6th the Korean crew of a tug bravely manned their vessel during the passage from Chinnampo to the Yellow Sea. The sailors of YMS 503 then brought their minesweeper into the port from offshore waters.
For the remainder of the Korean War, the men and ships of the Republic of Korea Navy operated in harm's way all around the peninsula. The ROKN not only continued to clear mines from coastal waters, in the process losing minesweeper YMS 306 and PC 704, but raided enemy-held islands, landed special warfare units and guerrillas behind the lines, fired on targets ashore, maintained a tight coastal blockade, and assisted other UN navies in the movement of troops, equipment, and refugees. Through hard fighting and the development of professional skills, by July 27, 1953 the Republic of Korea Navy had become a respected and valued member of the UN fighting team.
Alexander, Joseph H. Fleet Operations in a Mobile War: September 1950-June 1951. Naval Historical Center, 2001.
Buell, Thomas. B. Naval Leadership in Korea: The First Six Months. Naval Historical Center, 2002.
"Activity of the Republic of Korea Navy," in The History of the United Nations Forces in the Korean War. Vol. 1. Ministry of National Defense, Republic of Korea, 1972.
Field, James A. History of United States Naval Operations: Korea. Washington: Naval History Division, 1962.
Utz, Curtis A. Assault from the Sea: The Amphibious Landing at Inchon. Naval Historical Center, 1994.
Reproduced with permission from: Tucker, Spencer C. ed. Encyclopedia of the Korean War: A Political, Social, and Military History. Santa Barbara, CA: ABC-CLIO, 2000.