11
Oxygen Accumulation Bar Graph (O2BG)
The O2 Bar Graph (Fig. 2a) represents oxygen loading, show-
ing the maximum of either per dive accumulated oxygen, or 24
hour period accumulated oxygen.
As your oxygen exposure (accumulation) increases during the
dive, segments will add to the Bar Graph, and as loading
decreases, it will begin to recede, indicating that additional
exposure is allowed for that dive and 24 hour period.
Variable Ascent Rate Indicator (VARI)
The Variable Ascent Rate Indicator (Fig. 2b) provides a visual
representation of ascent speed (i.e., an ascent speedometer).
Green is a 'normal' rate, yellow a 'caution' rate, and red is 'Too
Fast'.
The segments of the Variable Ascent Rate Indicator represent
two sets of speeds which change at a reference depth of 60 feet
(18 meters). Refer to the chart for segment values.
WARNING: At depths greater than 60 feet (18
meters), ascent rates should not exceed 60 feet per
minute (18 meters per minute). At depths of 60 feet
(18 meters) and shallower, ascent rates should not
exceed 30 feet per minute (9 meters per minute).
Fig. 2 - O2BG and VARI
Variable Ascent Rate Indicator
Deeper than 60 feet (18 m)
Segments
Ascent Rate =
Displayed
FPM
MPM
0
0-20
0 - 6
1
21-50 6.5-15
2
51-60 15.5-18
3
>60
>18
60 feet (18 m) & Shallower
Segments
Ascent Rate =
Displayed
FPM
MPM
0
0-10
0 - 3
1
11-25 3.5-7.5
2
26-30 8-9
3
>
30
>
9
a
b
