Specifications

44
Wisdom 3 DC Manual
© 2002 Design, 2011 Doc. No. 12-5274-r01 (8/31/11)
DECOMPRESSION MODEL
The Decompression Model used by the Wisdom 3 is based on the no decompression multilevel repetitive dive
schedules successfully tested by Dr. Ray Rogers and Dr. Michael Powell. These tests did not include repeti-
tive dives deeper than 90 FT (27 M) or decompression dives. Due to the present unavailability of statistical
data, Wisdom 3 decompression predictions are based on U.S. Navy theory.
TISSUE COMPARTMENT CONTROL
The Wisdom 3 tracks twelve tissue compartments with halftimes ranging from 5 to 480 minutes. The Nitro-
gen Bar Graph always displays the controlling compartment that is the only one important at that time. Think
of the Nitrogen Bar Graph as 12 separate transparent displays laid on top of one another. The compartment
that has lled up fastest is the only one the viewer can see from the top.
At any particular point, one compartment may be absorbing nitrogen, while another that was previously high-
er may be off gassing. One compartment hand over control to another compartment at a different depth.
This feature of the Decompression Model is the basis of multilevel diving, one of the most impor-
tant contributions the Wisdom 3 offers you.
NO DECOMPRESSION LIMITS (NDLS)
Note how the No Decompression Limits for the Wisdom 3 are contrasted with the U.S. Navy limits (Fig. 92).
The WISDOM's Dive Planner does not scroll past 190 feet (57 meters), or to depths at which projected dive
time is less than one minute .
WARNINGS:
Using the Wisdom 3, just as using the U.S. Navy (or other) No Decompression
Tables, is no guarantee of avoiding decompression sickness (i.e., the bends).
Sherwood Scuba advocates responsible diving practices . Decompression diving is
inherently hazardous and greatly increases your risk of decompression sickness -
even when performed according to the computer's calculations.
In the event that you must make an emergency decompression dive, you must not
make another dive for at least 24 hours.
OXYGEN EXPOSURE LIMITS (OTLS)
Predicted exposure limits and oxygen calculations of the Wisdom 3 are based on maximum exposure dura-
tions published by the National Oceanic and Atmospheric Administration in the October 1991 NOAA Diving
Manual (Fig. 93).
Both central nervous system (CNS) oxygen toxicity and pulmonary oxygen toxicity were taken into consider-
ation when the limits were published by NOAA.
Although CNS oxygen toxicity is considered the primary constraint for higher levels of PO2, there are cir-
cumstances in which pulmonary oxygen toxicity can limit exposures.
CNS oxygen toxicity is not considered likely at PO2 levels below 1.30 ATA. It is however related to the div-
er's work level. Performing strenuous tasks could cause the symptoms of oxygen poisoning to occur at PO2
levels lower than they normally would appear during casual recreational diving.
WARNING: The nitrox features of the Wisdom 3 are intended for use only by
recreational divers trained for nitrox diving by an instructor certied by a recognized
training agency to teach diving with nitrox.
Diving with enriched nitrogen-oxygen (nitrox) mixtures requires special knowledge of the variations imposed
upon divers, their activities, and their equipment by the increased percentage of oxygen. Sherwood Scuba
recommends completion of a specialized Nitrox training course by a recognized training agency prior to div-
ing with any enriched nitrogen-oxygen (nitrox) mixtures.
Wisdom 3 USN
Depth NDL-mins. NDL
feet (meters) Eng (Metric) mins.
30 (9) 260 (283) - - -
35 - - - 310
40 (12) 137 (144) 200
50 (15) 81 (85) 100
60 (18) 57 (59) 60
70 (21) 40 (41) 50
80 (24) 30 (32) 40
90 (27) 24 (25) 30
100 (30) 19 (20) 25
110 (33) 16 (17) 20
120 (36) 13 (14) 15
130 (39) 11 (11) 10
140 (42) 9 (9) 10
150 (45) 8 (8) 5
160 (48) 7 (7) 5
170 (51) 7 (6) 5
180 (54) 6 (6) 5
190 (57) 5 (5) - - -
Fig. 92 - NDL
Comparison
Fig. 93 - OTLs
Maximum
Exposure Time
PO2
(ATA)
0.60
0.70
0.80
0.90
1.00
1.10
1.20
1.30
1.40
1.50
1.60
Per Dive
(Min)
720
570
450
360
300
240
210
180
150
120
45
Per 24hr
(Min)
720
570
450
360
300
270
240
210
180
180
150