distance

Definition/Scope: (1) The space between adjacent individual ships or boats measured in any direction between foremasts. (2) The space between adjacent men, animals, vehicles, or units in a formation measured from front to rear. (3) The space between known reference points or a ground observer and a target, measured in meters (artillery), in yards (naval gunfire), or in units specified by the observer.

Narrower Terms:

danger close distances
endurance distance
least separation distance
minimum safe distances
miss distance
safe separation distance
safety distance