Underwater Demolition Team in the context of United States Navy SEAL

United States Naval Construction Battalions, better known as the Navy Seabees, form the U.S. Naval Construction Forces (NCF). The Seabee nickname is a heterograph of the initial letters "CB" from the words "Construction Battalion". Depending upon context, "Seabee" can refer to all enlisted personnel in the USN's occupational field 7 (OF-7), all personnel in the Naval Construction Force (NCF), or Construction Battalion. Seabees serve both in and outside the NCF. During World War II they were plank-holders of both the Naval Combat Demolition Units and the Underwater Demolition Teams (UDTs). The men in the NCF considered these units to be "Seabee". In addition, Seabees served as elements of Cubs, Lions, Acorns and the United States Marine Corps. They also provided the manpower for the top secret CWS Flame Tank Group. Today the Seabees have many special task assignments starting with Camp David and the Naval Support Unit at the Department of State. Seabees serve under both Commanders of the Naval Surface Forces Atlantic/Pacific fleets as well as on many base Public Works and USN diving commands.

Naval Construction Battalions were conceived of as replacements for civilian construction companies in combat zones after the attack on Pearl Harbor. At the time civilian contractors had roughly 70,000 men working U.S.N. contracts overseas. International law made it illegal for civilian workers to resist an attack. Doing so would classify them as guerrillas and could lead to summary execution. The formation of the Seabees amidst the aftermath of the Battle of Wake Island inspired the backstory for the World War II movie The Fighting Seabees. They also feature prominently in the wartime musical drama (and subsequent film) South Pacific.

Green Light teams were small groups of U.S. Army Special Forces trained to advance, arm, and deploy Special Atomic Demolition Munitions (SADM) behind enemy lines. Created in 1962 during the height of the Cold War, they were responsible for infiltrating behind enemy lines to detonate atomic demolition munitions, a type of portable nuclear weapon created in 1954. The last teams were disbanded in 1986.