United States Naval Construction Battalions, better known as the Seabees, form the Naval Construction Force (NCF) of the United States Navy. Their nickname is a heterograph of the first initials "C.B." from the words Construction Battalion. Depending upon the use of the word, "Seabee" can refer to one of three things: all the enlisted personnel in the USN's occupational field-7 (OF-7), all officers and enlisted assigned to the Naval Construction Force, or the U.S. Naval Construction Battalions (CBs).

Naval Construction Battalions were conceived of as a replacement for civilian construction companies working for the US Navy after the United States was drawn into World War II with the Japanese attack on Pearl Harbor on 7 December 1941. At that time the U.S. had roughly 70,000 civilians working on military installations overseas. International law made it illegal for them to resist enemy attack, as to do so would classify them as guerrillas, for which they could be summarily executed, which is exactly what happened when the Japanese invaded Wake Island.

The Seabees would consist of skilled workers that would be trained to drop their tools if necessary and take up their weapons at a moment's notice to defend themselves. The concept model was that of a USMC–trained battalion of construction tradesmen (a military equivalent of those civilian companies) that would be capable of any type of construction, anywhere needed, under any conditions or circumstance. It was quickly realized that this model could be utilized in every theater of operations, as it was seen to be flexible and adaptable.

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