SUUNTO HELO2 - Manual (Page 64)

The depth of the ceiling and floor depends on your dive profile. The ceiling depth will
be fairly shallow when you enter the decompression mode, but if you remain at depth,
it will move downward and the ascent time will increase. Likewise, the floor and ceiling
may change upwards while you are decompressing.
When conditions are rough, it may be difficult to maintain a constant depth near the
surface. In such cases, it is more manageable to maintain an additional distance below
the ceiling, to ensure that the waves do not lift you above the ceiling. Suunto recom-
mends that decompression takes place deeper than 4 m/13 ft, even if the indicated
ceiling is shallower.
NOTE
It will take more time and more gas to decompress below the
ceiling than at the ceiling.
WARNING
NEVER ASCEND ABOVE THE CEILING! You must not ascend
above the ceiling during your decompression. In order to avoid
doing so by accident, you should stay somewhat below the ceiling.
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