Cochran COMMANDER User manual

www.divecochran.com
Cochran
COMMANDER
Owner's Manual
English - Imperial
Ver: CmdrAir-1.02
Manual Part Number: 4100811
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1
PRODUCT INTRODUCTION: The COMMANDER is
quite simple to use and operate, but underneath that
simplicity lies a significant level of sophistication. To
get the safest and most effective use of this
instrument, it is important that the user fully
understand the product. Please read and understand
this entire manual and know the principles and
practices of safe diving before using this device.
This Manual is divided into the following Sections:
Section Page
•Operation as an Air-only Dive Computer 1
•Alarm Clock Operation 10
•Touch Programming 13
•Warnings 19
•Configurable Items 22
•Specifications and Maintenance 26
•Liability, and Warranty 31
•Itemized Index and Subjects 38
SIDE CONTACTS:
CONTACT #2
CONTACT #1
CONTACT #3
The Contacts are used to let the user command the
unit to do a number of functions, communicate with a
PC for extracting information or configuring the unit,
and determining water conductivity. When Contacts 1
& 2 are shorted, the COMMANDER can detect the
difference between wet fingers, metal objects, fresh
water, salt water, and a PC interface probe.
TURNING ON THE COMMANDER: Although the
COMMANDER automatically turns on when it is
submerged in water, it is STRONGLY recommended
that the unit be manually powered up by wetting two
fingers and simultaneously touching Contacts 1 and 2
for two seconds. This allows the diver to ensure that
the unit is operating correctly and has adequate
battery capacity prior to entry. Once activated, the
unit will remain on for 60 minutes. If a dive is not
initiated within this 60 minutes, the COMMANDER

2
automatically shuts off. Notice that when Contacts 1
& 2 are first bridged, a short beep is issued which
indicates that the unit is recognizing the touch. Every
time Contacts 1 & 2 are bridged with wet fingers, the
unit will stay on for one full hour.
The COMMANDER will not turn on if the altitude is
higher than 15,000 feet, the batteries are less than 1.6
volts, or a fault is detected during the self-test.
As the COMMANDER first recognizes a turn-on
command, it begins a “Diagnostic” function where
many aspects of the system will be exercised and
tested. This procedure takes about three seconds
and an audible beep is issued each second as certain
tests are successfully completed. During this time, all
of the segments in the display are turned on so that
their operability can be confirmed by the user. Should
a test indicate a malfunction or marginal test, the unit
will turn back off again. The user should ensure that
all of the display segments are on and operating
correctly.
TURNING OFF THE COMMANDER: After the Post
Dive Interval following a dive, the COMMANDER will
remain on for one hour before automatically entering
its "Sleep Mode". During the Sleep Mode, all
calculations continue, but the display is off. This is a
power saving feature of the COMMANDER. The unit
will continue calculating Surface Interval,
compartment off gassing as required, and any
changes in altitude as it affects Nitrogen Loading.
The current Surface Interval and PreDive Predictions
can be viewed by reactivating the unit.
MAIN COMMANDER OPERATING MODES:
•Surface Interval (No Nitrogen Residual)
•Surface Interval (With Nitrogen Residual)
•Dive Mode (Normal No Deco)
•Decompression Mode
•Post Dive Interval
•Touch Programming

3
SURFACE INTERVAL:
After completion of the Self-Diagnostic mode or after
the Post Dive Interval following a dive, the
COMMANDER enters the Surface Interval. The
Screen displays, if applicable; current Surface Time,
the previous dive’s Maximum Depth, the previous
dive’s Bottom Time, Dive of Day number, current Time
to Fly, Altitude and Temperature. Figure 2 shows the
display with no residual Nitrogen (a clean Dive).
Figure 5 shows the display with residual Nitrogen (a
repetitive dive).
“Surface Time” starts at zero after a dive and begins
counting minutes. If the computer shuts off and is
turned on with Nitrogen residual left, the Surface Time
continues to count. If the computer shuts off and is
turned on with no Nitrogen residual left, the Surface
Time will be zero.
“Dive of Day” starts at zero and increments after each
dive regardless of the calendar day. When there is no
remaining Nitrogen residual, the Dive of Day is set to
zero and the computer is referred to as a “clean”
system.

4
“Time to Fly” is displayed as the number of hours
remaining until the Nitrogen residual reaches zero
plus a twelve-hour safety factor. Flying is not
recommended until Time to Fly reaches zero.
“Barometric Altitude” is indicated in six ranges via the
Ascent Rate Bar Graph as follows (Altitude
compensation is seamless up to 15,000 feet above
sea level):0 Bars sea level to 2,500 feet
1 Bar 2,500 to 5,000 feet
2 Bars 5,000 to 7,500 feet
3 Bars 7,500 to 10,000 feet
4 Bars 10,000 to 12,500 feet
5 Bars 12,500 to 15,000 feet
The six ranges are for display purposes only: The
COMMANDER actually senses and computes
extremely small altitude changes and hence, is called
“Seamless”. The term “Barometric Altitude” is used
instead of just “Altitude” because the COMMANDER
measures Barometric Pressure to determine Altitude.
Barometric Altitude can vary from actual Altitude by
over +/- 1000 feet! What is important to the body
when diving is Barometric Altitude.
DIVE MODE:
Whether in the Surface Interval, PreDive Prediction
Mode, Programming Mode or the Logbook Mode, the
COMMANDER will automatically enter the Dive Mode
whenever the unit determines that it is in water deeper
than five feet.
On the Display Screen the Surface time will be
replaced with the current Depth and be displayed in
one-foot increments. The maximum specified depth is
327 feet, but the unit will continue to measure and
display depths deeper that that. A Depth Sensor
warning will be issued (See later discussion on

5
Sensor Warnings) when the unit can no longer
accurately measure depth.
A Depth Alarm which can be set to warn the diver
should a certain depth be exceeded is set at 130 feet
from the factory. The Depth Alarm issues an audible
alarm and the “WARNING” legend and Depth Digits
will flash on and off for five seconds. The depth alarm
is disabled if in the Decompression Mode since
flashing depth digits have another meaning in this
Mode.
The maximum depth achieved on the current dive is
shown as “MAX DEPTH”. This is updated once per
second.
“REMAIN TIME” (NDC) is the remaining time (in hours
and minutes) that the diver can stay at the current
depth without requiring decompression. A “Two
Minute Warning” will be issued when this time reaches
two minutes or less. An audible alarm will be issued
and the “WARNING” legend and “REMAIN TIME”
digits will flash. By immediately ascending to a
shallower depth, the diver may avoid a required
decompression stop.
Temperature is measured for two purposes. One is to
compensate the Depth Transducer for Temperature
variations. The other is to compensate the Nitrogen
algorithm for changes in Temperature that may affect
the body. Both of these purposes require that the
Temperature be very slow reacting, just like the Depth
Transducer and the body. This slow-reacting
Temperature is what is displayed. For Temperature
effects on the body, the amount of compensation can
be set from NORMAL to REDUCED with the Analyst®
PC software Interface (see Analyst® Section), if the
diver is using a good dry-suit in cold water.
Temperature compensation starts at 75 degrees F
and gets progressively more conservative as the
temperature decreases. There is no compensation
above 75 degrees F.
Bottom Time will begin once the COMMANDER
senses that the diver has descended below five feet
(see Training Mode) and continues until the diver has
ascended above three feet. The maximum Bottom
Time displayed is 9 hours 59 minutes.
ASCENT RATE BAR GRAPH:
The Ascent Rate bar graph and alarms are active in
both the Dive Mode and Decompression Mode. The
five-segment bar graph is used to display the diver's
rate of ascent.

6
Via the Analyst®PC Interface, the Ascent Rate Alarms
and Bar Graph can be set to the users preferences.
The first option is a VARIABLE-BY-DEPTH Ascent
Rate. When on, the Ascent Rate Alarm is determined
by depth. As the diver ascends to shallow depths, the
Maximum Ascent Rate is lowered. The Maximum
Ascent Rates and their associated depth are:
60 feet or deeper 60 feet per minute
60 to 30 feet feet per minute equal to the depth
Less than 30 feet 30 feet per minute
If VARIABLE-BY-DEPTH is off, the Maximum Ascent
Rate Alarm and Bar Graph is specified by the user
and can be from 20 to 60 fpm, in one foot increments.
Another selection is the bar graph itself. The two
selections are either FIXED or PROPORTIONAL.
With FIXED, each of the five bars indicates an
additional 10 feet per minute of Ascent Rate
regardless of the Maximum Ascent Rate selected.
With PROPORTIONAL, each of the five bars indicate
20% (one-fifth) of the selected Maximum Ascent Rate.
For FIXED, the maximum ascent rate is 60 feet per
minute. With this setting, no bars will illuminate if a
diver is ascending at a rate less than 10 feet per
minute.
If the diver has an Ascent Rate that exceeds the
selected maximum, the entire Ascent Rate Bar Graph
will flash, and the audible alarm will sound once per
second, and the WARNING legend will illuminate.
The sensitivity or responsiveness of the Ascent Rate
may be selected via the Analyst®, eight different levels
of sensitivity are available.
NOTE: Customizing the Ascent Rate and Ascent
Rate Bar Graph are among many of the additional
programmable features available when using the
Analyst®PC Interface. Available features are
described in the section “USER CONFIGURABLE
OPTIONS”.
As shipped from the factory, the Ascent Rate is set for
VARIABLE-BY-DEPTH AND PROPORTIONAL.

7
DECOMPRESSION MODE:
Should a no-decompression limit be overstayed, the
COMMANDER will enter the Decompression Mode.
In this mode, the Ceiling digits will display the depth at
which the diver must stop and not ascend above
during final ascent. The “TEMP” legend and two digits
will be replaced with the “CEIL” legend and two digits.
The Ceiling will start at 10 feet and increase in ten-
foot increments as the diver remains at a relatively
deep depth.
The Remaining No-decompression Time and “NDC”
legend will be replaced with Decompression Time and
“DEC” legend (Figure 16d). Both STOP time and
TOTAL time are displayed in the upper left hand three
digits of the screen in hours and minutes. STOP and
TOTAL time will alternate at the rate of once every
two seconds. In this way, the diver can view the time
to spend at a particular STOP depth, and the TOTAL
time it will take to complete all STOPS. Clearly, the
larger of the two alternating numbers is the Total
Decompression Time of all stops, and the smaller of
the two numbers is the time required at the current
stop. At the ten foot stop, the TOTAL and STOP
times may be the same and therefore appear to not
alternate.
When at a specific stop, the required decompression
time at that stop is as shown, and will appear to count
down as it is recomputed every second, based on the
divers exact current depth. The Decompression times
(both Stop and Total) are accurate only if the divers
depth is exactly the same as the required Ceiling.
However, it is not necessary to be precisely at that
specified Ceiling. Appropriate In-gassing or Out-
gassing will be computed regardless of the divers
current depth.

8
A small margin shallower than the Ceiling also exists.
Should a Ceiling be ‘violated’ (diver is shallower than
Ceiling), the “WARNING” legend will illuminate and
flash along with the Depth and Ceiling digits. An
Audible alarm will sound once every two seconds.
This warning will continue until the Depth has been
corrected. Out-gassing will continue even though the
diver is shallower than the Ceiling. There is no
‘Gauge’ mode or ‘Lockout’ on the COMMANDER.
If the diver surfaces before satisfying his
decompression obligation, the COMMANDER will
continue to give out-gassing credit as if it were in a
dive, but at a depth of zero feet and will satisfy the
decompression time requirements of the required
stops using an FO2of 21%. The unit will continue to
log data and perform as if actually in a dive. When the
decompression obligation is finally satisfied, the ten-
minute “Post Dive Interval” will begin.
NOTE: COCHRAN does not intend for this instrument
to be used for deliberate Decompression diving.
POST DIVE INTERVAL:
During the first ten minutes (or up to thirty minutes if
the unit is in the Training Mode) after a dive, the
COMMANDER is in the Post Dive Interval. The
flashing "SURF" legend and a Surface Time of less
than ten minutes (or up to thirty if the unit is in the
Training Mode) indicate this. Should another dive be
commenced before the completion of the Post Dive
Interval, that dive will be considered an extension of
the previous dive. In this case, Bottom Time will NOT
include the time spent on the surface in this Post Dive
Interval. However, when reviewing the profile with the
Analyst®, the time spent on the surface in this period
will be shown.

9
CONFINED WATER PROTOCOL (Training Mode):
The COMMANDER is one of the first dive computers
to offer an operating mode designed to record and
store data from training dives. That is, dives
performed in shallow water environments (swimming
pools, shallow lakes, lagoons, etc.) or calm open
water environments that have less than 1-foot seas.
In the Training Mode, the COMMANDER enters the
Dive Mode at a depth of 2 feet instead of 5 feet and
will exit the Dive Mode at 1 foot instead of 3 feet. Also
the Post Dive Surface Interval may be extended, via
the Analyst®, from 10 minutes up to a maximum of 30
minutes in 1-minute increments after which the dive
data is stored in the computer's memory. These
changes permit the Instructor to record the complete
training session, including in-water surface periods, as
a single dive. The Training Mode can only be
enabled/disabled via the Professional Edition of
the Analyst®PC Interface.
TACLITE™: The COMMANDER is equipped with the
TACLITE™ tactical low-light fiber-optic backlighted
display. The standard TACLITE™ color is night vision
safe red, but it is also available in yellow for those
individuals who have vision difficulties with the color
red. The TACLITE™ can be activated on demand.
To turn the TACLITE™ on, tap the face of the
COMMANDER and the TACLITE™ will turn on for the
preprogrammed number of seconds (1 to 98), then
turn off. By tapping the face again the TACLITE™ will
turn on again. In this fashion the TACLITE™ can be
kept on for as long as wanted. If 0 is entered, the
TACLITE™ will never turn on. If 99 is entered, the
TACLITE™ will stay on continuously and only turn off
when the COMMANDER does. The number of
seconds that the TACLITE™ stays on can be set via
the Programming Mode or via the Analyst®PC
Interface, factory setting is 10 seconds. The
TACLITE™ will turn off when the COMMANDER turns

10
off. If the batteries get too low, the TACLITE™ will
turn off and cannot be turned back on until fresh
batteries are installed.
CLOCK MODE: The Clock operating mode of the
COMMANDER is NOT enabled when shipped from
the factory. It can be enabled via the Analyst® P.C.
Interface or at an Authorized Cochran Dealer.
TOUCH PROGRAMMING MODE: Can only be
accessed when the unit is in the Surface Interval and
allows the user to view or program into the dive
computer:
•Setting Clock and Alarm Time
•The PreDive Prediction Mode
•Displaying Mode, mode value, & battery voltage
•A Maximum Depth Alarm
•An Added degree of Conservatism from 0 to 50%
•Programming the On Time for the TACLITE™
•Access the Logbook Mode
TOUCH PROGRAMMING - CLOCK: When the
COMMANDER is placed into the Clock mode it will
display the time of day in a 24 hour day format. The
clock will continue to run when the COMMANDER is
in the Dive Computer Mode. The COMMANDER can
be placed into the Clock Mode from the Dive
Computer Mode when the unit is in the Normal
Surface Interval, while the unit is in Clock Mode the
Dive Computer will be in the “Sleep” mode.
The Clock Mode can be selected with or without an
Alarm. If the Alarm option is selected the unit will
display the alarm set time as well as the current time.
When the alarm time is displayed the alarm is
activated and at the programmed time the alarm will
sound once every 24 hours. When the alarm is
activated the unit will issue a medley of all the audible
warning tones that the COMMANDER utilizes and the
TACLITE™ will flash for one minute, this audible
alarm can not be turned off, it will sound for the full
one minute period.
The Clock Mode is selected via Touch Contact
Programming.
NOTE: This Time of Day clock is the same clock
that is used to time stamp dives. Modifying the
Time of Day clock will effect the Local Time as
viewed via the Analyst®. The Date portion of the
Local Time clock must be changed via the
Analyst®.

11
CLOCK PROGRAMMING PROCEDURE:
Contacts 1, 2, & 3 are for programming sequences.
To begin the programming sequence:
1. Turn the unit on;
2. Using a coin or other conductive metal object,
briefly bridge Contacts 1 and 2 until a short beep
is heard and the Clock Menu is seen on the
display.
3. To enter the Clock submenu, bridge Contacts 1
& 2 with wetted fingers. This will cause the unit
to display the Clock Alarm selection – On or
OFF. To Toggle the selection, bridge contacts
1&2 with wetted fingers.
4. Using a coin or other conductive metal object,
bridge Contacts 1 & 2 to access the Clock Time
or Alarm setting screen.
5. Shorting Contacts 1 & 2 with a coin will cause
the first digit of the minutes to flash.
6. Shorting Contacts 2 & 3 with a coin will
increment the numeric value, continue until the
required value is displayed. A confirmation beep
will sound with each increment.
7. Next using wetted finger, bridge Contacts 1 & 2
to select the next digit, once selected the digit
will flash to identify that it is being programmed.
Bridge Contacts 2 & 3 till the desired value is
displayed.
8. To select Hours short Contacts 1 & 2 with a coin,
increment as in step 6 and 7.
9. Repeat step 5 through 7 until all digits have been
programmed.
10. To save the changes that have been made
bridge Contact 1 & 2 with a coin or other
conductive metal object. Once the next
programming option is displayed the changes
have been saved.
To exit the Clock Mode Bridge contacts 1 & 2 with
wetted fingers and the computer will return to the Dive
Computer Mode’s Surface Display.
NOTE: Ensure that the COMMANDER is in the
Dive Computer Mode before commencing a
dive.
Figures 40, 41a, 41b, 42 and 43 show how the Clock
display screens appear.

12
NOTE: Once the COMMANDER is placed in Clock
Mode the unit will remain in that mode until
exited by the diver.
TOUCH PROGRAMMING MODE:
NOTE: To enable the Programming Mode, the
COMMANDER must be on the Surface and
not in the Post Dive Interval.
NOTE: All audible and visual alarms are
suspended while the COMMANDER is in
the Programming Mode. Upon exiting the
Programming Mode all alarms are
reactivated.

13
NOTE: Once a value has been changed and the
next menu option selected, the new value
is stored.
NOTE: It is strongly recommended that the
Programming Mode is activated again and
a complete review of what was stored is
accomplished.
NOTE: If the COMMANDER is left in the
Programming mode for five minutes
without the contacts being touched, the
unit will automatically exit the
Programming Mode and return to the
Surface Interval. Once this occurs the
COMMANDER will retain the modified
programmed settings that have been
stored. Options that have not been
modified will retain their previous settings.
TOUCH PROGRAMMING MODE - PROCEDURE:
Contacts 1, 2, & 3 are for programming sequences.
To begin the programming sequence:
1. Turn the unit on;
2. Using a coin or other conductive metal object,
briefly bridge Contacts 1 and 2 until a short beep
is heard and the Programming Menu is seen on
the display. The Programming Menu options
depend on whether the unit is activated for Clock.
The Menu options are displayed in sequence,
incrementing to the next selection each time that
Contacts 1 & 2 are bridged with a coin. The
program option is displayed on the upper row of
the display. The current setting for this option is
displayed in the lower right of the display.
3. To reprogram the displayed menu values, bridge
Contacts 1 & 2 with wetted fingers. This will
cause the current setting to flash or in the case of
multi-digit numbers, the least significant digit will
flash. The clock will toggle between on and off.
4. Using a coin or other conductive metal object,
bridge Contacts 2 & 3 to increment the numeric
value. A confirmation beep will sound with each
increment.
5. Next using wetted finger, bridge Contacts 1 & 2 to
select the next digit, once selected the digit will
flash to identify that it is being programmed.
Bridge Contacts 2 & 3 till the desired value is
displayed.
6. Repeat step 5 until all digits have been
programmed.

14
7. To save the changes that have been made bridge
Contact 1 & 2 with a coin or other conductive
metal object. Once the next programming option
is displayed the changes have been saved.
All programming sequences use the same routine of
using Contacts 1 and 2 to SELECT the next
programming sequence and Contacts 2 and 3 to
INCREMENT the specified value.
PROGRAMMING MODE MENU:
The following table lists the various programming
choices with their display identification and figure
number.
Identification Description Figure Page
CLC Clock – if enabled 40 12
PdP PreDive Prediction 22 14
InF Misc. Information 23 14
dEP AL Depth Alarm, Max value
is 320 feet 25 14
Con Added Conservatism, Max
value is 50%. 26 15
Tac dL TACLITE™ On Time. Allowed
value 0 to 99 33 15
LOG Logbook 34a 15

15
TOUCH PROGRAMMING - PREDIVE PREDICTION:
PreDive Prediction is accessed via the Touch Contact
Programming Menu. This enables the diver to view
the PreDive Prediction information at the touch of the
Contacts. The COMMANDER’s PreDive Prediction
starts at 30 feet and increases in 10 feet increments.
PreDive Predictions will terminate when the No-
Decompression (NDC) time prediction reaches two
minutes or a maximum depth of 320 feet is reached.
Additional Conservatism, Residual Nitrogen and
Barometric Altitude can effect PreDive Predictions.
Once the maximum PreDive Prediction depth has
been reached the unit will return to the Surface
Interval.

16
Refer to the Analyst®for information about how to
modify parameters. During the PreDive Prediction
Mode, the unit will compute and display the maximum
safe time and the calculated PO2value at that depth.
TOUCH PROGRAMMING INFORMATION DISPLAY:
The Information display is accessed via the
Programming Mode. The information presented will
appear as in Figure 24. The information in the upper
right of the screen indicates the unit is in the Air Only
FO2 Mode.
Identifier Description
F0 Air only
The Battery voltage is displayed in the lower center of
the screen as a two-digit number with a decimal point
proceeded by a lower case ‘b’. Figure 24 shows what
the display screen looks like for a Commander
configured for Air Only.
TOUCH PROGRAMMING - DEPTH ALARM: The
Depth Alarm allows the diver to select a maximum
depth below which the diver does not wish to descend
before an alarm is issued. This depth can be set from
0 to 320 feet in one foot increments.

17
TOUCH PROGRAMMING - CONSERVATISM: This
programming function allows the diver to input an
added degree of Conservatism into the Commander’s
nitrogen algorithm. Via Touch Programming the
Conservatism can be set from 0 to 50%.
TOUCH PROGRAMMING - TACLITE™:
The Taclite™ dwell (on) time can be set so that when
the face on the COMMANDER is tapped the Taclite™
will stay on from 1 to 98 seconds. If the dwell time is
programmed to ‘0’ the Taclite™ will never come on, if
programmed to 99 the Taclite™ will be on whenever
the COMMANDER is awake.
TOUCH PROGRAMMING - LOGBOOK:
The Logbook of the COMMANDER has two screens,
a Primary Screen and an Alternate Screen. To switch
to the Alternate Screen just tap firmly on the face of
the unit. The Logbook is accessed via the Touch
Contact Programming (see page 13). This enables
the diver to view dive statistics; the COMMANDER
has the ability to provide diving data for the most
recent 512 dives. The most recent dive will be
displayed first. To view the next dive, touch the
contacts 1 & 2 with wetted finger after pausing for a
few seconds. Do not use a metal object such as a
coin or knife-blade once in the Logbook since it will

18
cause the unit to exit the Logbook and return to the
Surface Interval.
Information contained in the Logbook will include:
Overall Dive Number Minimum NDC Time
Fastest Rate of Ascent Minimum Water Temperature
Bottom Time Surface Interval Before Dive
Maximum Depth Ending Battery Voltage
Beginning Dive Time & Date
Maximum DEC Time (Deco Dive)
Maximum Ceiling (Deco Dive)
It is not necessary to exit the Logbook Mode prior to
initiating a dive. Once the diver has descended below
five feet, the COMMANDER will immediately enter the
Dive Mode.
NOTE: The overall Dive Number that is displayed on
the Logbook Menu screen (Figure 34) permits the
diver to identify the total number of dives made with
that COMMANDER. If the logbook example shown is
the most recent dive made, it can be readily identified
that 235 dives have been made with this specific unit.
Figure 34b shows that dive 235 started at 14:26 hours
or 2:46 pm on the 18th of December 2001.
Figures 35 & 37b display the Logbook of a Normal
Dive.