UDTs in the Korean War

In 1947 two UDT teams commanded by Lieutenant Commander Cooper were assigned to Commander Amphibious Force, Pacific Fleet, and were based at Coronado, California. Two teams commanded by Lieutenant Commander Fane were assigned to the Commander Amphibious Force, Atlantic Fleet, and were based at Little Creek, Virginia. By 1948 the four UDT teams had a skeleton complement of 7 officers and 45 men each. With this small force they had to prepare for possible future wars, and try to maintain a combat readiness.

When the Korean War broke out in June, 1950, a 6-man detachment from UDT 3 was on duty in Japan. As the North Korean Army crossed the 38th Parallel and swept into the south, the UDT men boarded the flagship Admiral UDD Mount McKinley and headed for Korea. On July 4, 1950, just four days after the initial aggression by the Reds, General MacArthur was planning an amphibious assault on Inchon. A UDT reconnaissance of the beach of Pohang, conducted by LTJG George Atcheson and his boat crew, led to a successful landing on July 18, of 10,000 combat ready troops who boarded trains at Pohang and two days later met and repelled the Communist advance.

But the war raged on. Korea is a mountainous land,great rugged ranges spread out from the interior to the sea.US. Navy ships and aircraft cruised up and down the coast bombarding and bombing the bridges and tunnels, strafing the long lines of military vehicles and trains, and even blasting cliffs to pour landslides across the vital highways. Admiral Joy conceived the idea of organizing small amphibious raiding parties to harass the enemy by dynamiting their supply routes. UDT men in rubber boat crews performed the traditional beach reconnaissance missions and pioneered in sneak inland penetration missions to gather intelligence data and to destroy specific strategic targets such as roads or bridges in the near coastal areas.

Both of the Pacific coast teams, UDT 1 and UDT 3 officially arrived in Korea with their peacetime half-strength size of approx. 50 men each, in mid September of 1950. Their assignments included destroying a railway bridge and blowing up railroad tunnels to disrupt North Korean operations and supply lines. It was during the Korean War that UDT men pioneered in sneak inland penetration missions to gather intelligence data and to destroy specific strategic targets such as roads and bridges in the near-coastal area. Night insertion and reconnaissance became important in Korea.

Phil Carrico writes of UDTs in the '50s story one, two, three, four

UDT Operations in Korea: Inchon

UDT Operations in Korea: Taechon

UDT Operations in Korea: Wonsan

UDT Operations in Korea: Hungnam

UDT 5, a team newly commissioned to meet the Korean war duty, entered Wonsan waters aboard the Diachenko in February, 1952. Minesweeping occupied them until mid summer when their mission became destroying North Korean fishing nets to affect their food supply. These nets were huge, some 300' long, reinforced with steel cable. The men of UDT 5, while under fire from the enemy on shore, used bolt cutters and explosives to rip holes in the nets.

Otis Hackney - UDT 5 photo album

The armistice ended fighting on 27 July 1953. The men of UDT 1, UDT 3, and UDT 5 proved the readiness and outstanding capabilities of the "naked warriors". Meanwhile, UDT 2 and UDT 4, the Atlantic Fleet Teams, were involved in experimental programs involving the aqualung, lock-out from submerged submarines, cold-weather swimming systems, parachute training, and miniature submersibles.

On 8 February 1954, UDT 1, UDT 3, and UDT 5 were redesignated UDT 11, UDT 12, and UDT 13 respectively. UDT 2 and UDT 4 became UDT 21 and UDT 22. The Korean War marked a turning point in the history of the UDTs. In addition to their guiding amphibious forces ashore and obstacle demolition, the scope of their missions was expanded to include clearing obstructions from harbors, stealthily infiltrating waterways to attack enemy shipping and transport, clearing ordnance from the high seas, infiltrating and intelligence gathering, and covering the withdrawal of friendly forces.

In 1955 the UDTs carried out several missions in the icy waters of Alaska where their skills were put to good use to build the early warning radars needed to forestall any Soviet threat from the north.

In 1959 the UDTs lent a hand to the space program, experimenting with methods of astronauts training and space capsule recovery.

For photographs of Korean era Underwater Demolition Team men see:


Suggested reading:


Exploits of U. S. Navy Frogmen in Korea,  by Phil Carrico, ISBN 1-88774-527-0

Fifties Frogs - Journal of the Underwater Demolition Teams,  by Don Belcher and Bob Blann – self published

Korea Remembered,  by Charles F. Cole, autobiography, ISBN 1-8881325-13-X

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