During the Korean War and the Vietnam War, US Navy Special Warfare units played a variety of vital combat roles amid two of the deadliest conflicts of the Cold War. In Korea, underwater demolition teams (UDTs) surveyed beaches for amphibious operations, cleared sea mines from harbors, conducted seaborne raids against inshore targets, and served as scouts for the infiltration of Korean guerrillas and British Royal Marine Commando raids along the North Korean coast.