Garrett AT Pro Owner's Manual page 42

• Swing the searchcoil flat and at a constant height.
Do not bounce the coil and do not lift the coil at the end
of swings.
• Swing the searchcoil parallel to the water's edge.
• If necessary, notch out the first pixel under Foil. It is
important to note that by notching out this pixel,
detection of some small jewelry items will be reduced.
• The detector will be less stable in shallow, breaking surf
where the searchcoil is in and out of the saltwater.
In this area the detector is encountering a constantly
changing environment produced by the surf, making it
difficult for the detector to stabilize.
Tips for locating targets amongst terra cotta/hot rocks:
Magnetic minerals such as hot rocks and terra cotta can
mask the presence of good targets. In order to detect a good
target, first ground balance the AT Pro to the terra cotta or hot
rocks that are present.
Be aware, however, that the combined Target ID might
be very low (e.g. a bronze coin and terra cotta together
may register between 10 and 15 on the Digital Target ID).
Therefore, Iron Discrimination levels must be reduced in
order to ensure detection of good targets covered by the
terra cotta. The Iron Audio feature can also be used so that
all targets above the point of discrimination produce either a
medium or high tone (i.e. "good" targets).
42 Garrett Metal Detectors