Raymarine GPM400 Reference Manual page 49

When an alarm is triggered, a buzzer sounds and a pop-up window
describing the alarm and how to clear it is displayed. In some
cases, appropriate action is taken automatically by the G-Series
system. For example, following an arrival alarm, the next route leg
is activated.
To configure alarms
1. Press the MENU button to open the Setup menu.
2. Select Alarm Setup.
3. Choose the appropriate sub-menu.
4. For detailed information about alarm configurations, see Alarm
Setup Menu on page 194.
Chapter 5: The Chart Application
49