Suunto D4f User guide
Dive time alarm
The dive time alarm can be activated and used for several purposes to add to your diving safety. It is simply a countdown timer in minutes.
To set the dive time alarm:
- While in a relevant dive mode, keep pressed.
 - Press or to scroll to Alarm Time.
 - Press to toggle the alarm on and press to confirm.
 - Adjust the duration with or and accept with .
 - Press to exit.