Operation Thunderhead

Operation Thunderhead was a highly classified combat mission conducted by U.S. Navy SEAL Team One and Underwater Demolition Team 11 (UDT-11) in 1972. The mission was conducted off the coast of North Vietnam during the Vietnam War to rescue two U.S. airmen said to be escaping from a prisoner of war prison in Hanoi. The prisoners, including Air Force Colonel John A. Dramesi were planning to steal a boat and travel down the Red River to the Gulf of Tonkin.

Lieutenant Melvin Spence Dry was killed on the mission. He was the last SEAL lost during the Vietnam War. His father, retired Navy Captain Melvin H. Dry, spent the rest of his life trying to learn the circumstances surrounding his son's death. The details, however, were long shrouded in secrecy.

In April 1972, SEAL Team One left Subic Bay in the amphibious-transport submarine USS Grayback. The plan was to launch the team at night from the submerged submarine in a Swimmer Delivery Vehicle (SDV) piloted by two UDT-11 operators and head for a small island off the mouth of the Red River.

On 3 June 1972, Lieutenant Dry decided to conduct a clandestine reconnaissance mission that night. Shortly after midnight the team launched from Grayback but a combination of navigation errors and strong current took them off course. After an hour, the crew was compelled to abort the mission. They were unable to locate Grayback and they were forced to scuttle their underpowered SDV after its battery power was exhausted.

The next morning, the team was rescued a few miles off the coast. The four men were flown to the USS Long Beach, Operation Thunderhead's command ship.

At 2300 hours on 5 June, the men were to be transported back to Grayback by helicopter. The team would perform a night water drop next to the submarine. During briefings with the pilots, Lt. Dry and Chief Warrant Officer (CWO) Martin emphasized the maximum limits for the drop were 20/20-- 20 feet of altitude at an airspeed of 20 knots, or an equivalent combination.

When the helicopter arrived near Grayback's expected position, they could not locate the submarine. As they desperately searched for the submarine's beacon, Lt. Dry and his men prepared to enter the water and lock into the submerged submarine.

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