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V Diving with microbubble levels (MB)
V UWATEC
®
Smart dive computers
The following chapter deals with the characteristics of diving with microbubble levels (MB levels).
For general information about displays and features of diving with TEC see chapter III.
Microbubbles
are tiny bubbles that can build up inside a diver's body during any dive and normally dissipate
naturally during an ascent and on the surface after a dive. Dives within no-stop time and observance of decom-
pression stops do not prevent the formation of microbubbles in the venous blood circulation.
Dangerous microbubbles are those migrating into the arterial circulation. The reasons for the migration
from the venous blood circulation to the arterial circulation can be a great many microbubbles collecting in
the lungs. UWATEC has equipped Smart dive computers with a new technology to protect from microbubbles.
The diver chooses – according to his/her needs – an MB level and influences through it the level of pro-
tection from microbubbles. Diving with MB levels requires additional ascent stops (level stops), the ascent is slo-
wed down and the body gets more time to desaturate. This works contrary to the formation of the microbub-
bles and increases the safety.
Smart TEC features
6 microbubble levels
(L0-L5). Level L0 corresponds to UWATEC's well-known
decompression model ZH-L8 ADT and does not require level stops due to microbubble formation. Levels L1
to L5 offer additional protection from microbubble formation with level L5 offering the highest protection.
Similar to the display of information during decompression dives or dives within no-stop time, TEC displays
depth and duration of the first level stop as well as the total time of ascent as soon as the MB no-stop time
has run out. As the MB no-stop time is shorter than the ordinary no-stop time a diver will be required to carry
out a stop (level stop) sooner than a diver using level L0.
If a diver ignores a required level stop, TEC will change over to a lower MB level and the dive can not be
completed with the initially chosen MB level. E.g. If a diver sets level L4 on TEC prior to the dive and during the
dive ignores the stops recommended TEC will automatically adjust the setting to level L3 or lower.
1 Comparison of dives with MB level L0 and MB level L5
When two Smart TECs are used simultaneously, one unit is set for example to MB level L5, the other to
L0, the no-stop time will be shortened and level stops will be required before the diver has the obligation
of a decompression stop. These additional level stops help dissipate the microbubbles.
3m/10ft
6m/20ft
9m/30ft
12m/40ft
15m/50ft
Time
Depth
Micr
obubble
level
Microbubble accumulation
at the end of dive
Stop depth
L0
L5
L0
L5
m
DECO
STOP
m
LEVELSTOP
m
LEVELSTOP
NO STOP
m
LEVELSTOP
NO STOP
NO STOP
NO STOP
DECO
ft
ft
ft
ft
Decompression values
Level stop values
Decompression obligation, ->31
