United States Naval Construction Battalions, better known as the Navy Seabees, form the U.S. Naval Construction Force (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 13 (OF-13), 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.
CB Navy Yard Bougainville with the Seabee Expression
3rd Marine Div. 2nd Raider's sign on Bougainville. 53rd CB was the shore party to the 2nd Raiders of Green Beach, D-Day.
CEC Insignia
Supply Corps Insignia
Underwater Demolition Team
The Underwater Demolition Team (UDT), or frogmen, were amphibious units created by the United States Navy during World War II with specialized non-tactical missions. They were predecessors of the navy's current SEAL teams.
Patch of the Underwater Demolition Teams.
U.S. Naval Combat Demolition insignia. – U.S. Navy Seal Museum
"NCDU 45"; Ensign Karnowski, Chief Carpenters Mate Conrad C. Millis, MMCB2 Lester Meyers and three gunners mates. The unit received a Presidential Unit Citation with Ens. Karnowski earning the Navy Cross & French Croix de Guerre with Palm, while MM2 Meyers received a Silver Star. Two men were wounded and one was killed.
80-G-258013 At Morotai NCDU 21 with MacArthur's 7th Fleet makes a channel using 8 tons of explosives in a single blast. Debris was thrown 800 yards or nearly a half mile.