Suunto D4 User Manual page 42

When programming the instrument for the correct altitude, you need to select the
correct Altitude Adjustment settings according to Table 5.5, Altitude Adjustment settings.
The dive computer will adjust its mathematical model according to the entered altitude
setting, giving shorter no-decompression times at higher altitudes (see Table 10.1,
No-decompression time limits for various depths (m) and Table 10.2, No-decompression
time limits for various depths (ft) in Section 10.2. RGBM).
Table 5.5. Altitude Adjustment settings
Alt. adjustment value
A0
A1
A2
NOTE
WARNING
Altitude range
0 - 300 m / 0 - 1000 ft
300 - 1500 m / 1000 - 5000 ft
1500 - 3000 m / 5000 - 10 000 ft
Section 5.8.5. Setting the personal/altitude adjustments describes
how the Altitude value is set.
Traveling to a higher elevation can temporarily cause a change
in the equilibrium of dissolved nitrogen in the body. It is recom-
mended that you acclimatize to the new altitude by waiting at
least three hours before diving.
43