BOTTOM ALARM
The Wide 3D View contains an audible alarm to warn you of shallow water depths. This alarm is adjustable from 2' to 99' of depth. To enable the alarm, simply adjust the alarm depth using the UP and DOWN arrow buttons, and press ENTER. When the depth of the water beneath your boat is equal to or less than the selected alarm depth, a continuous alarm will sound.
To disable the alarm, either move to deeper water, or select the Bottom Alarm menu, and press ENTER to turn the alarm off.