B&G Network Quad - Manual (Page 17)

THE DEPTH DATUM - CAL
The depth datum CAL is an offset calibration value used to
determine the displayed information reference point. It is
added to the actual measured water depth to display the
depth from the waterline, the depth sensor (transducer) or
the keel/outdrive depth.
The Network QUAD unit has factory set CAL of zero, i.e.
the depth is displayed from the transducer. The CAL value
is displayed in the same units as the depth.
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