Underwater Demolition Teams
Shoulder sleeve patch of the Underwater Demolition Teams
Active	August 15, 1942 - January 1, 1983
Branch	United States Navy
Type	Amphibious warfare
Role	reconnaissance, infiltrating and exfiltrating by sea, underwater demolition, intelligence gathering
Garrison/HQ	Fort Pierce, Florida Maui
Nickname	UDT
Engagements	Operation Overlord Korean War Battle of Iwo Jima Battle of Okinawa Operation Torch Borneo campaign (1945) Battle of Peleliu Battle of Saipan Battle of Tinian Battle of Guam Battle of Leyte Gulf Invasion of Lingayen Gulf

Underwater Demolition Teams (UDT) were a precursor to the current United States Navy SEALs. The UDTs conducted beach and hydrographic reconnaissance, explosive cable and net cutting, explosive destruction of underwater obstacles to enable major amphibious landings, limpet mine attacks, submarine operations, and the locating and marking of mines for minesweepers. They also conducted river surveys and foreign military training. While doing this, the UDTs pioneered combat swimming, closed-circuit diving, underwater demolitions, and midget submarine (dry and wet submersible) operations.^[1]

Contents 1 Early history 1.1 Training 1.2 Normandy 1.3 South Pacific 2 Cold War operations 2.1 Korean War 2.2 Vietnam 2.2.1 Birth of Navy SEALs 3 UDT badge 4 UDTs in fiction 5 See also 6 References 7 External links

[edit] Early history

By the time America became involved in World War II, Adolf Hitler and his Axis forces had control over a large portion of Europe, Asia and North Africa. If the Allied forces were to stand a chance, there would have to be several full-scale landings. America recognized the need for intelligence that covered landing sites during World War I following a disastrous landing on the beach of Gallipoli, which was aborted after 30,000 troops landed only to find the terrain forbidding.

The United States Navy decided that to do the job right required sending in their own. They needed brave men to reconnoiter the landing beaches, take note of obstacles and defenses and ultimately guide the landing forces in. Later, during the war, the Army Engineers passed down demolition jobs to the U.S. Navy. They were to clear any obstacles and/or defenses in the near shore area. Beginning a tradition that continues today, these brave men contributed immensely to the war effort.

The Amphibious Scout and Raider School was established in 1942 by joint-Army and Navy at Fort Pierce, Florida. It was intended to train explosive ordnance disposal personnel and experienced combat swimmers from the Army and Marine Corps, becoming the Naval Combat Demolition Unit, or NCDU.^[2] They were trained by then-Lieutenant Commander Phil H. Bucklew and then later, then-Lieutenant Draper L. Kauffman. The NCDU was first employed in Operation Torch during the invasion of North Africa in 1942. This unit became the 'first group' specialized in amphibious raids and tactics in the United States Navy.^[2]

By 1943, Kaufman has expanded the Amphibious Scout and Raider School into a syllabus in a more of a Navy-oriented school for underwater demolition. Following the near-disaster of the landing force on Tarawa in November of 1943 due to the obstacles in the surf, then-Rear Admiral Richmond K. Turner directed the formation of nine Underwater Demolition Teams mostly composed of navy personnel from the Naval Construction Battalions (Seabees). Further, then-Rear Admiral Richmond K. Turner has also implemented the establishment of the Navy Experimental and Tactical Demolition Station on Waimānalo, Oahu later moving to Kamaole, Maui in the Hawaiian Islands.^[2] These volunteers were organized into special teams and were tasked with reconnoitering and clearing beach obstacles for troops going ashore during amphibious landings, and evolved into Combat Swimmer Reconnaissance Units, becoming the Navy UDTs.^[2]

[edit] Training

Under-Water Demolition Teams began training in June 1943, one year before the invasion of Normandy. Admiral Ernest J. King ordered Navy Combat Demolition Training to commence in order to cope with the obstacles that Hitler would undoubtedly use to hinder landings in Europe.

Admiral King picked a Reserve Officer, Lieutenant Draper L. Kauffman to lead UDT training, which began at Fort Pierce near the Scouts and Raiders. Most of Kauffman's volunteers came from the Navy's Construction Battalions, Marines and Army Combat Engineers. Training commenced with one grueling week designed to "separate the men from the boys". Some said that "the men had sense enough to quit, and left the boys". It was and is still considered the first "Hell Week."

Kauffman, later 'augmented' to a regular Navy commission, went on to serve as Superintendent of the Naval Academy, and retired as a Rear Admiral on June 1, 1973.

The training made the use of inflatable boats and surprisingly little swimming. The assumptions were that the men would paddle in and work in shallow water leaving the deep-water demolitions to the Army. The Marine Reconnaissance units would conduct the hydrography from shallow water to inland while the accompanying UDT would conduct the demolition and hydrography from near-deep water to the shallow. The UDT teams were organized with approximately sixteen officers and eighty men. A single Marine and a single Army officer were liaison within each team.^[3] It became apparent that a UDT assigned to a particular beach as the Marine counterpart to ride along the same high speed transport ships, or APDs.

At this point, the men were required to wear Navy fatigues with shoes and helmets. They were ordered to be lifelined to their boats and stay out of the water as much as possible. Kauffman's experience was at disarming explosives; now he and his teams were learning to use them offensively. One innovation was to use 2.5-pound (1.1 kg) packs of tetryl placed into rubber tubes, thus making 20-pound (9.1 kg) lengths of explosive tubing that could be manipulated around obstacles for demolition.^[4]

Dr. Chris Lambertsen, who had been working with the maritime unit for the Office of Strategic Services (OSS), demonstrated the Lambertsen Amphibious Respiratory Unit (LARU), an oxygen rebreather, to LCDR Kauffman in October 1943. At this time, the outcome of the meeting showed there was no place in current operations for this radically new device.^[5][6] Closed-circuit oxygen diving and combat swimming continued under the oversight of Dr. Lambertsen and the OSS. Following President Truman's dissolving the OSS in 1945, Lambertsen retained the LARU inventory and later began training the US Army Engineers, the US Coast Guard, and U.S. Navy UDT personnel.^[5] In 1947, LCDR Doug Fane, saw the advantages of having the teams trained in the use of SCUBA gear for future operations.^[5][7] LCDR Fane was unable to arrange this training in 1947 following an evaluation by the US Navy Experimental Diving Unit and the Navy Dive School and invited Dr. Lambertsen to NAB Little Creek, Virginia in January 1948 to demonstrate and train the UDT personnel in SCUBA operations.^[5] This was the first-ever training for Navy divers in SCUBA. Following this training, Fane and Lambertsen demonstrated new UDT capabilities with a successful lock-out and re-entry from USS Grouper (SS-214), an underway submarine, to prove a national navy need for this type of training.^[5] LCDR Fane then started the classified “Submersible Operations” or SUBOPS platoon with men drawn from UDT 2 and 4 under the direction of LTJG Bruce Dunning.^[5][8]

[edit] Normandy

On D-Day, six men from Kauffman's Naval Combat Demolition Unit Eleven (NCDU-11) were sent to England in the beginning of November 1943 to start preparations to clear the beaches for the Normandy invasion. Later NCDU 11 was enlarged into 13-man assault teams.

Field Marshal Erwin Rommel had implemented the intricate defenses found on the French coastline. These creatively included steel posts driven into the sand and topped with explosives. Large 3-ton steel barricades called Belgian Gates were placed well into the surf zone. Additionally, he strategically placed reinforced mortar and machine gun nests. The Scouts and Raiders spent weeks gathering information during nightly surveillance missions up and down the French coast. Replicas of the Belgian Gates were constructed on the South Coast of England for the UDT to practice demolitions on. The strategy of the UDT was to knock the gates flat, not to shred and spread them along the beaches, thereby creating more of an obstacle for the advancing troops.

Men supported by naval offshore artillery led the initial attack on the two American landing beaches of Omaha and Utah. Then a first wave of tanks and troop carriers were to land and clear any remaining German bunkers and snipers. The Demolitions Gap-Assault teams would come in with the second wave and work at low tide to clear the obstacles.

As happens often during the fog of war, the Allied aircraft ended up dropping their bombs too far inland. Navy artillery then sent the majority of their shells far over the German positions - wreaking havoc on the French farmlands but leaving the well-positioned German guns in perfect operating condition. These guns sent withering ground fire against the approaching Allied forces. The tides also ended up pushing many of the demolition crews well ahead of the first wave. They found themselves the first to land on the beaches. Many of the teams were killed by machine gun and mortar fire before reaching the beach. Other team members under enemy fire managed to set charges on the obstacles and blow them. At one point, soldiers were taking cover behind the obstacles, which were emplaced with demolitions charged with timers. The GIs quickly made their way onto the beaches to avoid becoming a friendly casualty of war. The mission was to open sixteen 50-foot (15 m) wide corridors for the landing. By nightfall only thirteen were open, and these beaches exacted a heavy toll on the Navy Gap-Assault teams.

Of the 175 UDT men on Omaha beach, 31 were killed and 60 wounded. Their teammates on Utah Beach fared far better because the beach was considerably less fortified. Four were killed and eleven wounded, when an artillery shell landed among one of the teams working to clear the beach. Weeks before the invasion, all available Underwater Demolition men were sent from Fort Pierce to England. The largest loss occurred at the landing on Omaha beach, Normandy. Within months of the war's end, the UDT teams were dispersed. This ended a trying but evolutionary time in the history of Naval Special Warfare.^[9]

[edit] South Pacific

After a major catastrophe on the island of Tarawa, the need for the UDT in the South Pacific became glaringly clear. The islands in this region have unpredictable tide changes and shallow reefs that can easily thwart the progress of the naval transport vessels. At Tarawa, the first wave made it across the reef in Amtracs, but the second wave in Higgins boats got stuck on a reef left exposed by the low tide. The Marines had to unload and wade to shore. Many drowned or were killed before making the beach. The Amtracs, without reinforcements from the second wave, were slaughtered on the beach. It was a valuable lesson that the Navy would not permit to be repeated. The Navy Combat Swimmers were turned to for an answer.

The V (Fifth) Amphibious Force set up training at Waimanalo, on the coast of Oahu in the Hawaiian Islands. Attending were men from Fort Pierce as well as men from the Army and Marines. Represented were the Scouts and Raiders as well as the Naval Combat Demolitions Teams. Under the direction of Amphibious Reconnaissance Company,^[10] they hastily trained for the attack on Kwajalein on 31 January 1944. This was a major turning point for the tactics of the UDT. The plan was to send in night reconnaissance teams such as the Scouts and Raiders were accustomed to. Then Admiral Turner, worried about the presence of obstacles emplaced by the Japanese, ordered two daylight reconnaissance operations.

The missions were to follow the standard procedure. Team one was to go in a rubber boat in full fatigues, boots, life jackets and metal helmets. The coral reef kept their craft too far from shore to be certain of the beach conditions. Ensign Lewis F. Luehrs and Chief Petty Officer Bill Acheson made a decision that changed the shape of Naval Special Warfare forever. Removing all but their underwear, they swam undeterred across the reef. They returned with sketches of the beach gun embankment locations, along with information about a log wall built to deter landings and other vital intelligence. Naval Combat Swimming had now entered onto the Mission Essential Task List of the UDT. There were up to 19 official UDT teams. Team 10 was directly under the OSS. It had a secret base on Santa Catalina Island, California before the Maui base was operational.

After Kwajalein, the UDT created the Naval Combat Demolition Training and Experimental Base on Maui. Operations began in April 1944. Most of the procedures from Fort Pierce had been modified, with importance placed upon developing strong swimmers. Extensive training was conducted in the water without lifelines, using facemasks and wearing swim trunks and shoes in the water. This new model gave us the image that stands today of the WWII UDT "Other Naked Warrior". The landings continued and at Iwo Jima the surveying teams fared favorably. The largest casualties of the UDT occurred not in the water, but aboard the destroyer USS Blessman (DE-69) after it was struck by Japanese bomber. When the bomb exploded in the mess hall, fifteen men on the UDT Team were killed. Twenty-three others were injured. This was by far the most tragic loss of life suffered by the UDT in the Pacific theater.

Up until now all the islands worked upon were in southern waters. Soon the forces moved North toward Japan. Having no thermal protection, the UDT men were at risk of hypothermia and severe cramps. This problem was extreme during the surveying of Okinawa. The largest UDT deployment in the war employed veteran Team's Seven, Twelve, Thirteen, Fourteen and newly trained teams Eleven, Sixteen, Seventeen, and Eighteen. Close to a thousand UDT forces worked in concert on operations both real and deceptive to create the illusion of landing in other locations. Pointed poles set into the coral reef of the beach protected the landing beaches on Okinawa. Team's Eleven and Sixteen were sent in to blast the poles. After all the charges were set, the men swam to clear the area and the following explosion took out all of Team Eleven's and half of team Sixteen's targets. Team Sixteen broke from the operation due to the death of one of their men; hence, their mission was considered a failure and a disgrace. Team Eleven was sent back the following day to finish the job and then remained to guide the forces to the beach. The UDT continued to prepare for the invasion of Japan. After the atomic bomb exploded over Hiroshima and Nagasaki, the war quickly ended. The need for an invasion of Japan was averted and the UDT's role in the South Pacific came to an end.^[11]

[edit] Cold War operations

At the end of the 1950s, there were few Special Operations Forces. The Army had Special Forces, and the Navy had Underwater Demolition Teams (UDT). These elite units were trained to fight and operate behind the lines of a conventional war, specifically in the event of a Soviet drive through Europe.

[edit] Korean War

The end of World War II saw a major decline in the UDT. The remaining officers and enlisted men were dedicated, hard working men. Before the start of the Korean War, the UDT were testing uses of the Underwater Breathing Apparatus (UBA) and developing weapons skills and commando operations on land in coastal regions.

They also started experiments with insertion/extraction by helicopter, jumping from a moving helicopter into the water or rappelling like mountain climbers to the ground. Experimentation developed a system for emergency extraction by plane called "Skyhook." Skyhook utilized a large helium balloon and cable rig with harness. A special grabbing device on the nose of a C-130 enabled a pilot to snatch the cable tethered to the balloon and lift a person off the ground. Once airborne, the crew would winch the cable in and retrieve the personnel though the back of the aircraft. This technique was discontinued for training purposes after the death of a SEAL at NAB Coronado on a training lift. The teams still utilize the Fulton Skyhook for equipment extraction and retain the capability for war if an extreme situation requires it.

The UDT refined and developed their commando tactics during the Korean War, with their efforts initially focused on demolitions and mine disposal. Additionally, the UDT accompanied South Korean commandos on raids in the North to demolish train tunnels. The higher-ranking officers of the UDT frowned upon this activity because it was a non-traditional use of the Naval forces, which took them too far from the water line. Due to the nature of the war, the UDT maintained a low operational profile. Some of the better-known missions include the transport of spies into North Korea and the destruction of North Korean Fishing nets used to supply the North Korean Army with several tons of fish annually.

The Korean War was a period of transition for the men of the UDT. They tested their previous limits and defined new parameters for their special style of warfare. These new techniques and expanded horizons positioned the UDT well to assume an even broader role as the storms of war began brewing to the South in the Vietnamese Peninsula.^[12]

[edit] Vietnam

The Navy entered the Vietnam conflict in 1960, when the UDTs delivered small watercraft far up the Mekong River into Laos. In 1961, Naval Advisers started training the Vietnamese UDT. These men were called the Lien Doc Nguoi Nhia (LDNN), roughly translated as the "soldiers that fight under the sea."

President John F. Kennedy, aware of the situations in Southeast Asia, recognized the need for unconventional warfare and utilized special operations forces as a measure against guerrilla activity. In a speech to Congress in May 1961, Kennedy shared his deep respect of the Green Berets. He announced the government's plan to put a man on the moon, and, in the same speech, allocated over one hundred million dollars toward the strengthening of unconventional forces in order to expand the strength of the conventional forces.

[edit] Birth of Navy SEALs

Realizing the administration's favor of the US Army Special Forces, the Navy needed to determine its role within the special operations arena. In March 1961, the Chief of Naval Operations recommended the establishment of guerrilla and counter-guerrilla units. These units would be able to operate from sea, air or land. This was the beginning of the official Navy SEALs. Many SEAL members came from the Navy's UDT units, who had already gained experience in commando warfare in Korea; however, the UDTs were still necessary to the Navy's amphibious force.

The first two teams were on opposite coasts: Team One at Naval Amphibious Base Coronado, California and Team Two at Naval Amphibious Base Little Creek, Virginia. The men of the newly formed SEAL Teams were educated in such unconventional areas as hand-to-hand combat, high altitude parachuting, safe-cracking, demolitions and languages. Among the varied tools and weapons required by the teams was the AR-15 assault rifle, a new design that evolved into today's M16. The SEALs attended UDT Replacement training and they spent some time cutting their teeth at a UDT Team. Upon making it to a SEAL Team, they would undergo a three-month SEAL Basic Indoctrination (SBI) training class at Camp Kerry in the Cuyamaca Mountains. After SBI training class, they would enter a platoon and train in platoon tactics (especially for the conflict in Vietnam).

The Pacific Command recognized Vietnam as a potential hot spot for conventional forces. In the beginning of 1962, the UDT started hydrographic surveys and Military Assistance Command Vietnam (MACV) was formed. In March 1962, SEALs were deployed to Vietnam for the purpose of training South Vietnamese commandos in the same methods they were trained themselves.

The Central Intelligence Agency began SEAL covert operations in early 1963. At the outset of the war, operations consisted of ambushing supply movements and locating and capturing North Vietnamese officers. Due to poor intelligence information, these operations were not very successful. When the SEALs were given the resources to develop their own intelligence, the information became much more timely and reliable. The SEALs and special operations in general started showing an immense success rate, earning their members a great number of citations.

The SEALs were initially deployed in and around Da Nang, training the South Vietnamese in combat diving, demolitions and guerrilla/anti-guerrilla tactics. As the war continued, the SEALs found themselves positioned in the Rung Sat Special Zone where they were to disrupt the enemy supply and troop movements, and into the Mekong Delta to fulfill riverine (fighting on the inland waterways) operations. The brown water of the Delta provided the foundation for the development of SEAL riverine operations. The SEALs adapted quickly and with deadly results. The braces, inlets and estuaries intermingled and left a broad area for both the North and South to operate. The SEALs and Brown Water Navy Boat Crews made it their job to win this part of the war, impeding as much as possible the movement of troops and supplies coming from the North.

The SEAL teams experienced this war like no others. Combat with the Viet Cong was very close and personal. Unlike the conventional warfare methods of firing artillery into a coordinate location, or dropping bombs from thirty thousand feet, the SEALs operated within inches of their targets. SEALs had to kill at short range and respond without hesitation or be killed. Into the late 1960s, the SEALs made great headway with this new style of warfare. Theirs were the most effective anti-guerrilla and guerrilla actions in the war.

However, back in the United States, the politics of the war were working against the administration. The anti-war protests became much louder by the end of the sixties. The American public began to question this war that was claiming so many of their young men. The anxiety and anger caused by the war began to take its toll and violence erupted at home.

SEALs continued to make forays into North Vietnam and Laos, and unofficially into Cambodia, controlled by the Studies and Observations Group. The SEALs from Team 2 started a unique deployment of SEAL team members working alone with South Vietnamese Commandos. In 1967, a SEAL unit named Detachment Bravo (Det B) was formed to operate these mixed US/ARVN units, which were called South Vietnamese Provincial Reconnaissance Units, or PRUs.

In the beginning of 1968, the North Vietnamese and the Viet Cong orchestrated a major offensive against South Vietnam. Virtually every major city felt the effects of the "Tet Offensive." The North hoped it would prove to be America's Dien Bien Phu. They wanted to break the American public's desire to continue the war. As propaganda the Tet Offensive was successful: America was weary of a war that could not be won, for principles no one was sure of. However, North Vietnam suffered tremendous casualties, and from a purely military standpoint the Tet Offensive was a major disaster to the Communists.

By 1970, the US decided to remove itself from the conflict. President Richard Nixon initiated the plan of Vietnamization, which would return the responsibility of defense back to the South Vietnamese. Conventional forces were being withdrawn, however, operations of the SEALs continued. The SEALs had developed a new base at the tip of the Ca Mau Peninsula and created a floating firebase, now known as Seafloat, by welding together fourteen barges. Accessible from sea, it also provided a landing area for helos.

On 6 June 1972, Lt. Melvin S. Dry was killed when entering the water after jumping from a helicopter at least 35-feet above the surface. Part of an aborted SDV operation to retrieve Prisoners of War, Lt. Dry was the last officially recorded SEAL killed during the Vietnam conflict.^[13]

[edit] UDT badge

For those who served in an Underwater Demolition Team, the U.S. Navy authorized a military badge known as the Underwater Demolition Badge. The badge was phased out and eventually replaced by the Special Warfare Badge. In the modern age, the Underwater Demolition Badge is considered obsolete.

[edit] UDTs in fiction

• The Frogmen was a film released in 1951, starring Dana Andrews and Richard Widmark, based on the UDT teams. The action in the story is about WWII and featured real Korean-War era UDT members in several sequences.

• In Tom Clancy's "Without Remorse" a novel about the background of John Kelly a recurring character in Tom Clancy's Ryanverse, In "Without Remorse" John Kelly is originally a UDT expert and later becomes one of the first SEALs.

[edit] See also

• Clearance Diving Teams
• Former United States special operations units
• Underwater demolition
• United States Navy SEALs
• United States Special Operations Forces
• U.S. Marine Amphibious Reconnaissance Battalion

[edit] References

Notes

Bibliography

• The National Navy UDT-SEAL Museum website
• Cunningham,Chet,The Frogmen of World War II: An Oral History of the U.S. Navy's Underwater Demolition Teams (ISBN 0743482166)

[edit] External links

• Navy UDT-SEAL Museum
• NavyFrogMen.com U. S. Naval Special Warfare Archives