20
ALADIN ONE USER MANUAL
3.6 Diving in mountain lakes
3.6.1
Altitude classes
The Aladin One measures the atmospheric pressure every 60 seconds, even while the
display is switched off. If the computer detects a sufficient increase in altitude, it switches
on automatically and indicates the new altitude class (1-4) and the desaturation time.
Desaturation time indicated at this moment refers to the adaptation time at this altitude. If
the dive starts within this adaptation time, the Aladin One treats it as a repetitive dive, since
the body is off-gassing.
Altitude is divided into 5 classes, which are influenced by barometric pressure. That is why
the defined altitude classes overlap on their fringes. If a mountain lake is reached, the altitude
class is indicated at the surface (time of day display), in the logbook and in the dive planner
with a stylized mountain icon and the current altitude class. The altitude from sea level to
approximately 1000m/3280ft is not indicated. In the following diagram, you can see the
approximate breakdown of the altitude classes:
Altitude Class
Elevation Barometric
switch point
Dive computer
mode
GAUGE
(no deco data)
SCUBA
SCUBA
SCUBA
SCUBA
3.6.2
Prohibited altitude
Ascent to altitude class 3 and 4 is
prohibited. Maximum allowed altitude:
2650m/8694ft.
WARNING
At the surface, the Aladin One shows, via flashing
altitude class number, the altitude to which you
may not rise. The ascent prohibition is displayed
together with the current altitude class.
Example:
You are at 1200m/3937ft (altitude class
1) and you may ascend to class 2 only
(2650m/8694ft). You may not rise to the
altitude classes 3 or 4.
WARNING
If an ascent to a prohibited altitude is detected,
an audible alarm sounds for 1 minute. Descend
to a lower altitude.
3.6.3
Decompression dives in
mountain lakes
In order to assure optimal decompression
even at higher altitudes, the 3m/10ft
decompression stage is divided into a
4m/13ft stage and a 2m/7ft stage in
altitude classes 1, 2 and 3. The prescribed
decompression stop depths are in sequence
(2m/7ft, 4m/13ft, 6m/20ft, 9m/30ft…).
If atmospheric pressure is below
620mbar/8.99psi (altitude higher than
4100m/13450ft above sea level), no
decompression data is calculated and
displayed (automatic gauge mode). In
addition, the dive planner is no longer
available.
