Suunto Cobra User Manual page 27

The ascent time (ASC TIME) is the minimum amount of time needed to reach the
surface in a decompression dive. It includes:
• the time needed to ascend to the ceiling at an ascent rate of 10 m/min
[33 ft/min] plus
• the time needed at the ceiling. The ceiling is the shallowest depth to
which you should ascend plus
• the time needed at the Mandatory Safety Stop (if any) plus
• the 3 minute Recommended Safety Stop plus
• the time needed to reach the surface after the ceiling and safety stops
have been completed.
YOUR ACTUAL ASCENT TIME MAY BE LONGER THAN DISPLAYED
BY THE INSTRUMENT! The ascent time will increase if you:
- remain at depth
- ascend slower than 10 m/min [33 ft/min] or
- make your decompression stop deeper than at the ceiling.
These factors will also increase the amount of air required to reach the
surface.
CEILING, CEILING ZONE, FLOOR AND DECOMPRESSION
RANGE
When in decompression, it is important that you understand the meaning of ceiling,
fl oor, and decompression range (Fig. 3.20.):
• The ceiling is the shallowest depth to which you should ascend when in
decompression. At this depth, or below, you must perform all stops.
• The ceiling zone is the optimum decompression stop zone. It is the zone
between the minimum ceiling and 1.8 m [6 ft] below the minimum
ceiling.
• The fl oor is the deepest depth at which the decompression stop time will
not increase. Decompression will start when you pass this depth during
your ascent.
• The decompression range is the depth range between the ceiling and
fl oor. Within this range, decompression takes place. However, it is
important to remember that the decompression will be very slow at, or
close to, the fl oor.
WARNING!
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