Humminbird 300 SERIES 345C DI - Manual (Page 82)

Depth Offset
(Advanced)
Settings: -10.0 to +10.0 feet, or -3.0 to 3.0 meters
[International Models only]; Default = 0 feet
Depth Offset will adjust the digital depth readout to indicate depth from the
waterline or boat's keel. Enter a positive vertical measurement from the
transducer to the waterline to read the depth from the waterline. Enter a
negative vertical measurement from the transducer to keel to read the depth
from the keel.
Temp. Offset
(Advanced)
Settings: -10.0 to +10.0 degrees, Default = 0
Temp. Offset will adjust the temperature readout by the amount entered.
Default Sonar View Sonar View with Select Readouts
Setup Menu Tab 73