that you know your focus and IPD settings so that the
binoculars may be properly adjusted at night or when
there are no objects on which to focus in the daytime.
For nighttime use, the focus setting is one mark less
than for daytime.
Contrary to widespread opinion, it is not always
better to search with binoculars instead of using the
naked eye. Several factors govern when and how
binoculars should be used. In fog, for instance, they
should be used only to identify a previously sighted
contact; at night, they should be used quite often.
Daytime use of binoculars depends upon the type
of search being conducted. Surface lookouts should
use them to scan across their sector, then use the naked
eye on return sweeps. Sky lookouts should use them
only to identify a target detected with the naked eye.
At night the binoculars should be used more
frequently than during daylight, but searches should
still be made with the naked eye. You often can see
objects, particularly moving ones, out of the corner
of your eye, whereas they might not be detected with
the binoculars because of their narrow field of view.
Binoculars should never be used to scan in fog, rain,
snow, or thick haze, but may be used to identify a
contact detected by the naked eye.
Binoculars are fairly delicate instruments; they can-
not stand much knocking about. Therefore, keep them
on a short strap when wearing them to prevent their
banging against solid objects. Keep the lenses dry,
otherwise you will not be able to see properly. Do not
let them become overheated; the cement around the