Operating instructions

Ft./Min M/Min.
a= 21 - 30 6 - 9
b= 31 - 40 9.1 - 12
c= 41 - 50 12.1 - 15
d= 51 - 60 15.1 - 18
e= 61 - 70 18.1 - 21
f= 71+ 21.1+
Figure 9
Ascent Rate Values
e. Compartment Loading Bar Graph (CLBG). As you dive, the Matrix
monitors the nitrogen absorption of 12 tissue groups simultaneously
and displays the controlling tissue group via the CLBG. The CLBG has
three sections: The green zone means you are within the no-decom-
pression limits; the yellow zone means you are approaching decom-
pression and should start your ascent; the red zone means you’ve
exceeded the no-decompression stop limits and must perform a
decompression stop. When the bar graph reaches the red zone, the
Matrix will switch to decompression dive mode and give you all the
necessary decompression stop information.
f. Ascent Rate Indicator. The ascent rate indicator consists of six
triangles that appear, from bottom to top, as your ascent rate
increases. Figure 9 shows each triangle with its corresponding ascent
rate. While making your ascent to the surface, always try to keep the
ascent rate indicator in the green zone. If it enters the yellow caution
zone, slow down or stop until the triangles recede into the green zone.
If the ascent rate indicator enters the red zone, you are making an
unsafe ascent and risk the possibility of decompression sickness.
While in the red zone, the ascent rate indicator flashes. Always make
an ascent such that the ascent rate indicator never enters the red
zone.
DECOMPRESSION DIVE MODE
WARNING: U.S. Divers does not recommend decompression diving
or diving deeper than 130 feet. Doing so increases the risk of
decompression sickness.
When you exceed the no-decompression time limits, the Matrix enters Decompression Dive
Mode (figure 10). There are three visual cues that alert you that you are in decompression:
1. The last segment of the compartment loading bar graph (a) has entered the red zone.
2. The “DECO” label (b) appears.
3. The ceiling indicator (c) flashes.
As soon as the Matrix enters Decompression Dive Mode, the maximum depth is replaced
with the depth of the first decompression stop (d), and the bottom time is replaced with
the decompression stop time (e). Also, no-stop time is replaced with total ascent time (f).
Total ascent time is the sum of all your decompression stop times plus the ascent time to
the first stop at a rate of 60 ft/min. The example shown in figure 10 shows that the diver
must make a 20-foot (6 m) stop for 3 minutes, with a total ascent time of 14 minutes.
After entering decompression, it is imperative that you begin your ascent immediately.
Ascend to a depth slightly deeper than or equal to 10 feet. The amount of decompression
credit time depends on the depth, with slightly less credit given the deeper you are.
Figure 10
Decompression Dive Mode
You must never ascend shallower than the prescribed decompression stop depth (ceiling). Doing so will put the Matrix
into a Conditional Violation Mode (see page 32) and greatly increase your risk of decompression sickness. If there is
heavy surge or large swells, it is difficult to stay at a chosen depth. To ensure that you do not enter a violation mode,
stay slightly deeper than the required decompression stop depth until the next shallower stop depth appears. For
example, if you are required to make a 20-foot (6 m) decompression stop, perform the stop at 23 or 24 feet (7 or 7.5
m) until the computer tells you to ascend the 10-foot (3 m) stop. Then perform the 10-foot (3 m) stop at 13 or 14 feet
(4 or 4.5 m) until you clear the decompression requirement.
Once you complete all the necessary decompression stops, the Matrix returns to normal Dive Mode, allowing you
additional time underwater. To add a greater margin of safety, U.S. Divers strongly recommends that you wait until the
segments of the CLBG are well within the green zone before surfacing, unless a low air situation dictates that you
surface.
At the end of all decompression dives, spend as much time as possible at your safety stop and on the surface to reduce
your compartment loading before the next dive.