What is Underwater Demolition?

During World War II, US Navy UDTs (Universal Deployable Teams, commonly referred to as “frogmen”) were specially trained to investigate and eliminate obstacles obstructing amphibious landings. They also pioneered combat swimming, closed-circuit diving, and midget submarine (dry and wet submersible) operations. Find the best Demolition Modesto.

UDTs were subjected to size cuts at the conclusion of World War II but would go on to play an instrumental role in future victories, including Korea.

Hydrographic Reconnaissance

Early in World War II, the Navy didn’t have much information about enemy beaches that would help guide Allied amphibious landing craft. This was especially true for coastal areas where both German and Japanese forces had built heavy fortifications that could hamper amphibious operations. To address this, the UDTs were created – predecessors of today’s SEAL Teams – and these “frogmen” were trained to swim into enemy beaches, find out what was there, and destroy obstacles that would pose dangers to landing craft.

The UDT swimmers would dive down to about 50 feet from the beach and locate coral reefs, rocks, shoals, and any man-made underwater obstacles. They also surveyed the beach’s exits, slope, ability to support foot or vehicle traffic, and any other data that would be useful to military commanders preparing for an assault.

Ideally, the recon and explosives placement would be clandestine and timed so that the enemy wasn’t expecting an invasion. In fact, this is the type of mission that BUD/S Third Phase trains future SEALs to carry out. During the training, trainees make breath-hold dives down to fix haversacks full of explosives onto manmade underwater obstacles that are then blown up. This is to simulate what the SEALs might have to do in an actual World War II-style amphibious invasion.

Inland Demolition Raids

When the Navy first created its elite underwater demolition units, also known as frogmen, in World War II, they had to clear obstacles on enemy-held beaches before amphibious landings. They did this by destroying coastal defenses, clearing paths through mine-infested waters for boats, and rescuing sailors from sunk minesweepers. Their work was essential to the Allied victory.

During the Korean War, UDTs expanded their mission scope beyond beach-clearing, proving they were more than just a team of skilled swimmers. They took part in daring night-time raids, clearing shallow-water minefields and carrying out underwater sneak attacks. Today’s Navy SEALs have inherited this skill set and can execute a wide range of missions.

To become a member of a UDT, a Sailor must undergo rigorous training to qualify as an exceptional swimmer. In addition to a year of physical and psychological testing, these men undergo weeks of specialized combat diving and other tasks.

The training regimen was so demanding that the Navy’s original UDT school, called the Amphibious Scout and Raider School, had an attrition rate of about 50 percent. To lower the attrition, the Navy tried to cut training hours and reduce the amount of stress on recruits. However, these efforts did not significantly change the attrition rate. Attempting to make the program less demanding could ultimately derail UDT training, which has to push recruits far beyond their limits and help them develop the mental strength to carry out these hazardous missions.

Shallow-Water Mine Clearance

When it comes to underwater mine clearance, the Navy’s legacy of special operations dates back to World War II. It was then that the Navy established its first underwater demolition teams, or “frogmen,” to clear obstacles on enemy-held beaches prior to amphibious landings in Europe and the Pacific.

These swam ahead of the landing craft and cleared paths through the mine-infested waters so they could safely make their way ashore. Frogmen also played a vital role in the Inchon Landing in Korea, acting as waveguides to guide Marines during their amphibious assault on Wonsan Harbor and performing daring night coastal demolition raids to destroy railroad tunnels and bridges that were critical to North Korean forces.

During this period, the UDTs started to expand their mission scope beyond beach clearing. They began conducting nighttime raids against critical infrastructure like railroad tunnels and bridges to weaken the enemy’s defenses. This bold action proved that the frogmen were more than just beach-clearing experts. Today’s Navy SEAL teams continue to carry this legacy forward by expanding their mission sets similarly, executing reconnaissance, unconventional warfare, and sabotage missions.

To accomplish these missions, Navy divers are trained to operate in various environments, including shallow water, deep water, and even the open sea. Deeper-water deployments require additional training and equipment, including the AQS-20/X sensor, which couples side-scan and gap-fill sonars with an electro-optical detection system.

Underwater Sneak Attacks

With the end of World War II came military downsizing, and UDTs were one of many units to be cut. But as the Cold War began, they found themselves once again called upon for their unique talents. They could still perform hydrographic reconnaissance, inland demolition raids, and shallow-water mine clearance, but they also had the capability to carry out submarine sneak attacks.

Treat a submarine sneak attack like regular combat, but instead of rolling for hits during the general combat portion, the submarine submerges itself and then fires a “surprise strike” against enemy destroyers. This only works when no other destroyers are present in the battle.