Garmin GPSMAP 168 Sounder Owner's Manual And Reference Manual page 85

Reference
Main Menu:
Alarm Tab
Setting the Clock Alarm
Press ENTER/MARK to acknowledge
an alarm and clear the message.
76
To set an alarm:
1. Use the ARROW KEYPAD to highlight the fi eld to the right of the alarm name you wish activate
and press ENTER/MARK.
2. Change the mode to 'On' (Distance or Time for the 'Arrival' alarm) and press ENTER/MARK.
3. Highlight the next fi eld to the right and press ENTER/MARK, then enter the desired settings and
press ENTER/MARK to fi nish.
I
In order to hear an audible alarm, you must have the beeper turned on (page 69).
When an alarm is activated, a message will appear at the bottom of the display screen
(pages 83-84).