Sixteen-inch guns of the USS Iowa bombarding enemy intallations in North Korea.

Photo Caption: Sixteen-inch guns of the USS Iowa (BB-61) bombarding enemy intallations in North Korea.

The U.S. Navy's primary role at the outset of the Korean War was to help the United Nations Command (UNC) avert a disaster in the Far East. The mobility of the U.S. Pacific Fleet and the forward basing of its major combat element, the Seventh Fleet, allowed President Harry S. Truman to support his decision to oppose what he saw as a communist challenge in Asia. Soon after the North Korean invasion, he announced that the United States, as part of a U.N. coalition, would use military force to preserve the sovereignty of the Republic of Korea. Truman also made it clear that the use of Chinese communist forces, and by implication Soviet air and naval forces to broaden the war in Asia, would be challenged. During the first week of the war, Seventh Fleet aircraft carrier USS Valley Forge (CV-45), heavy cruiser USS Rochester (CA-124), eight destroyers and three submarines were especially busy. The fleet displayed its strength along the Chinese coast. Valley Forge air squadrons also bombed airfields and rail yards in Pyongyang, North Korea, then beyond the range of the U.S. Air Force planes in Japan. The North Korean capital was the nerve center of the enemy's military establishment.

With the recent release of documents from the archives in Moscow and Beijing, it is now clear that the Navy's rapid show of force deterred the Chinese communists from carrying out a long-planned amphibious assault on the island of Taiwan, which was held by anti-communist Chinese Nationalist forces. An invasion of Taiwan would have widened the conflict in the Far East. Moreover, the quick deployment to the Far East of U.S. naval and land-based air forces influenced Soviet Premier Josef Stalin to withdraw an earlier pledge of Soviet air support for the North Korean attack.

Throughout the Korean War, U.S. Navy submarines and aircraft patrolled between the Soviet Union and the combat theater, not only to warn of surprise attacks, but to discourage such attacks. Other submarines and patrol planes, and periodically carrier task forces, operated off the long Chinese coast in a similar deterrence role.

Maintaining Sea Superiority

The object of the Navy's combat operations was to maintain superiority at sea and in Far Eastern skies. It was no coincidence that at no time during the war did the People's Republic of China or the Soviet Union use the sea or the air above it to support communist forces on the Korean Peninsula. The fleet's presence in the Western Pacific and its quick move to Korean waters also helped MacArthur's Far East Command to slow down the enemy's 1950 ground offensive, hold a precarious beachhead on the peninsula and build up forces ashore for a counteroffensive.

One of the allies' first actions was to destroy North Korean naval vessels. The North Korean navy operated only 45 small vessels, but they were pressed into the enemy's initial assault primarily to transport supplies to forces advancing along both coasts. In the early hours of the attack, the enemy also used naval vessels in a bold, strategic attempt to seize Pusan by landing 600 troops near the port. Pusan was one of South Korea's largest ports, and its location in southeastern Korea across from logistic support bases in Japan also made it vital to the allied cause. A North Korean victory there could have doomed the allied effort to retain a toehold in South Korea. But those 600 enemy troops never landed: Enemy ships were sunk by American naval gunfire. F4U's (Corsairs) returning from a combat mission over North Korea circle the USS Boxer (CV-21) as they wait for planes in the next strike to be launched from her flight deck.

Photo Caption: F4U's (Corsairs) returning from a combat mission over North Korea circle the USS Boxer (CV-21) as they wait for planes in the next strike to be launched from her flight deck.

The Tide of Battle Turns at Inchon

The fleet's great mobility and control of the seas enabled General MacArthur and the U.N. Command to turn the tide of battle. In mid-September 1950, Commander Seventh Fleet and Commander Task Force 7 Vice Admiral Arthur D. Struble led an armada of 230 amphibious and other ships in a surprise amphibious assault on the port of Inchon on Korea's west coast. Named Operation CHROMITE, the 1st and 5th Marine Regiments of the 1st Marine Division spearheaded the attack. Enemy and allied leaders alike had doubted that a major amphibious operation could be successful at Inchon, where the high tide ranged between 23 and 35 feet. At low tide, attacking ships faced the risk of being stuck in the mud. Furthermore, two fortified islands blocked access to the port of Inchon. Following days of bombardment by carrier planes and shelling by cruisers, destroyers and other naval gunfire support ships, elements of the 5th Marines, part of X Corps, initiated the assault at 6:33 a.m., Sept. 15. By the early morning hours of Sept. 16, their objectives had been secured.

MacArthur hoped for another Inchon-like landing on the eastern coast of North Korea. What slowed the amphibious operation was the fleet's discovery of between 2,000 and 4,000 Soviet-supplied magnetic and contact mines blocking the approaches to the port at Wonsan. Several U.S. Navy minesweepers were sunk before the troops could land. The setback at Wonsan resulted from the Navy's prewar reductions in the mine warfare force, failure to provide adequate equipment and general inattention to mine warfare. Despite the difficulties at Wonsan, the Task Force 95 minesweeping force registered some successes, such as the loss-free opening of the sea channel to Chinnampo, the port serving captured Pyongyang.

In November 1950, the Communist Chinese People's Liberation Army entered the war to assist the North Korean Army. The X Corps found itself outnumbered and dangerously overextended in the heart of North Korea. The allied command decided that X Corps, comprised of the 1st Marine Division and the Army's 3d and 7th Infantry Divisions, and three South Korean divisions of the I and II Corps would be evacuated by sea from the eastern ports of Hungnam and Wonsan.

Naval Support at Chosin

The withdrawal operation began on Dec. 10, 1950, when Task Force 90 embarked elements of the 1st Marine Division, which had just finished an arduous, masterful fighting withdrawal from the Chosin Reservoir. Fleet carriers Philippine Sea (CV-47), Valley Forge (CV-45), Princeton (CV-37) and Leyte Gulf (CV-32) and three escort carriers had provided the American ground troops with crucial close-air support. Navy and Marine Corps aviators carried out more than 1,700 sorties during only one week of the operation. At the same time, the battleship Missouri, cruisers St. Paul (CA-73), and Rochester and a score of destroyers and rocket ships provided a ring of fire around the embarking allied troops. More than 23,000 16-inch, 8-inch, 5-inch and 3-inch rounds and rockets fell on Chinese and North Korean forces moving against the U.N. defensive perimeter. By Christmas Eve, when Navy explosive teams destroyed the port facilities at Hungnam, the Navy had withdrawn 105,000 troops, 91,000 civilian refugees, 350,000 tons of cargo and 17,500 military vehicles. Another 3,600 troops, 1,300 tons of cargo and 196 vehicles had been airlifted out by Air Force and Marine Corps aircraft. Clearly, the Navy's control of the sea enabled the X Corps to live to fight another day.

Blockading the Coastlines

The navies of the U.N. coalition also maintained a blockade of North Korea's coastlines. This prevented the enemy from using the sea and also allowed allied vessels to move about in relative freedom. This strategic advantage also enabled U.N. Command surface ships and submarines to land U.S. Navy underwater demolition teams (UDTs), U.S. Marines, British Royal Marine commandos, South Korean commandos and other special forces on both Korean coasts and on many coastal islands. The elite units destroyed enemy railways and railway tunnels, highway bridges and supply depots. U.N. naval forces also landed Korean guerrillas ashore for long operations behind enemy lines. In a major effort from Feb. 16, 1951, to the end of the Korean War, the fleet prevented the enemy from using the port of Wonsan by subjecting it to bombardment by air units, battleships, cruisers and destroyers of Task Force 95. One history of the war also credits this operation with diverting 80,000 North Korean troops from frontline duty.

Sea control was especially important during the last two years of the war, when the enemy launched numerous ground operations whose objectives were to force the U.N. to withdraw its troops from Korea — the best-case scenario — or to improve their negotiating position in the cease-fire talks held at Panmunjom. Sea power was a major factor in frustrating these communist goals and persuading the enemy to sign the Armistice agreement ending the Korean War on July 27, 1953.

Those Who Served

More than 265,000 Navy personnel served in Korea during the war — a sizeable proportion of the 5,720,000 other Americans who answered the call to duty. Four hundred seventy-five Navy personnel were killed in action; another 4,043 sailors died from disease or injury; and 1,576 were wounded in action during this first major conflict of the Cold War era.


Cagle, Malcolm W. and Manson, Frank A. The Sea War in Korea (1957).

Field, James A. History of United States Naval Operations: Korea (1962).

Hallion, Richard P. The Naval Air War in Korea (1986).

Marolda, Edward J. "The U.S. Navy in the Korean War," in The Korean War: An Encyclopedia (1995).

Summers, Harry G. Jr. Korean War Almanac (1990).

For additional information contact:

The Naval Historical Center
805 Kidder Breese St., SE
Washington Navy Yard
Washington, D.C. 20374-5060