What is Danger Close?
1.
In close air support, artillery, mortar, and naval gunfire support fires, it is the term included in the method of engagement segment of a call for fire which indicates that friendly forces are within close proximity of the target, usually 600 metres however The close proximity distance can be determined by the weapon and munition fired.
"steelrain, steelrain, this is Hitman calling in fire mission, popeye uniform 059 098 038 degrees 200 metres, danger close"
"roger that hitman, splash in 5 seconds"
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2.
Used in military radio traffic to inform some one that the sending unit has enemy contact very near their exact position.
*Marine* Sir, it's so damn dark, I can't see 'em, but I can smell 'em.
*Marine Captain speaking into radio* Echo 2 Charlie be advised we have danger close.
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