Suunto D9tx, D9t Series User Manual

User’s GUide

en

SUUNTO D9tx

1. WELCOME TO THE WORLD OF SUUNTO DIVE COMPUTERS . .... .. .. .. .. .. .. 8

2. WARNINGS, CAUTIONS, AND NOTES . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 9

3. SUUNTO USER INTERFACE . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 16

3.1. Navigating in the menus . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 17

3.2. Button symbols and functions . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 19

4. GETTING STARTED .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 21

4.1. TIME mode settings .............................................................. 21

4.1.1. Setting the alarm ............................................................ 22

4.1.2. Setting the time .............................................................. 23

4.1.3. Setting the dual time ........................................................ 23

4.1.4. Setting the date .............................................................. 24

4.1.5. Setting the units ............................................................. 24

4.1.6. Setting the backlight .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 25

4.1.7. Setting the contrast ......................................................... 25

4.1.8. Setting the tones .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 26

4.2. Stopwatch .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 26

4.3. AC water contacts . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 27

4.4. Learning how to use your compass ............................................ 28

4.4.1. Compass display . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 29

4.4.2. Locking a bearing . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 30

4.4.3. Compass settings .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 31

5. BEFORE DIVING ...................................................................... 35

5.1. The Suunto Technical RGBM . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 35

5.2. Emergency ascents . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 36

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5.3. Dive computer limitations . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 36

5.4. Mixed gas diving .................................................................. 37

5.5. Audible and visual alarms .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 37

5.6. Error conditions . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 42

5.7. Wireless transmission .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 43

5.7.1. Installing the wireless transmitter . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 43

5.7.2. Pairing and code selection . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 44

5.7.3. Transmitting data . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 47

5.8. DIVE mode settings .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 48

5.8.1. Setting the gases . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 50

5.8.2. Setting the personal/altitude adjustments .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 51

5.8.3. Setting the tank pressure pairing . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 52

5.8.4. Setting the tank pressure alarm . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 53

5.8.5. Setting the depth alarm . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 53

5.8.6. Setting the dive-time alarm . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 54

5.8.7. Setting the sample rate . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 54

5.8.8. Setting the deep stops . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 55

5.8.9. Setting the units ............................................................. 55

5.9. Activation and pre-checks ....................................................... 55

5.9.1. Accessing DIVE mode ...................................................... 56

5.9.2. DIVE mode activation ....................................................... 56

5.9.3. Battery power indication . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 58

5.9.4. Diving at altitude . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 59

5.9.5. Personal adjustments . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 60

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5.10. Safety Stops . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 63

5.10.1. Recommended Safety Stops . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 63

5.10.2. Mandatory Safety Stops .................................................. 64

5.11. Deep stops . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 65

6. DIVING . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 67

6.1. Diving in the AIR mode (DIVE Air) ............................................. 67

6.1.1. Basic dive data . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 68

6.1.2. Bookmark . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 69

6.1.3. Tank pressure data . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 70

6.1.4. Ascent rate indicator ........................................................ 72

6.1.5. Safety Stops and Deep Stops .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 73

6.1.6. Stopwatch (Timer) . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 73

6.1.7. Decompression dives . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 74

6.2. Diving in the MIXED mode .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 79

6.2.1. Before diving in the MIXED mode ......................................... 79

6.2.2. Oxygen and helium displays .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 81

6.2.3. Oxygen limit fraction (OLF%) . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 82

6.2.4. Gas change and multiple breathing gas mixes .......................... 83

6.3. Diving in the GAUGE mode (DIVE Gauge) . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 84

7. AFTER DIVING ......................................................................... 86

7.1. Surface interval ................................................................... 86

7.2. Dive numbering . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 87

7.3. Repetitive dive planning . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 88

7.4. Flying after diving ................................................................. 88

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7.5. DIVE PLANNING mode (PLAN NoDec) .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 89

7.5.1. Dive numbering shown during dive planning . .. .. .. .. .. .. .. .. .. .. .. .. .. . 91

7.6. MEMORY mode . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 91

7.6.1. Dive logbook (MEM Logbook) ............................................. 92

7.6.2. Dive history .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 94

7.7. Suunto DM4 with Movescount . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 95

7.8. Movescount .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 96

8. CARE AND MAINTENANCE OF MY SUUNTO DIVING COMPUTER .. .. .. .. .. 97

9. BATTERY REPLACEMENT ......................................................... 102

9.1. Computer battery replacement ................................................ 102

9.2. Wireless transmitter battery replacement .................................... 103

9.2.1. Transmitter battery kit . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 103

9.2.2. Required tools .............................................................. 103

9.2.3. Replacing the transmitter battery .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 103

10. TECHNICAL DATA . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 106

10.1. Technical specifications ....................................................... 106

10.2. RGBM .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 109

10.2.1. Suunto Technical RGBM decompression model . .. .. .. .. .. .. .. .. .. .. 110

10.2.2. Suunto RGBM adaptive decompression .............................. 111

10.2.3. Altitude diving .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 112

10.3. Oxygen exposure .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 113

11. INTELLECTUAL PROPERTY .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 115

11.1. Copyright ........................................................................ 115

11.2. Trademark . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 115

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11.3. Patent notice .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 115

12. DISCLAIMERS ...................................................................... 116

12.1. User’s responsibility .......................................................... 116

12.2. CE ............................................................................... 116

13. SUUNTO LIMITED WARRANTY FOR SUUNTO DIVING COMPUTERS AND

SUUNTO DIVING COMPUTER ACCESSORIES . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 117

14. DISPOSAL OF THE DEVICE . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 122

GLOSSARY . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 123

7

1. WELCOME TO THE WORLD OF SUUNTO DIVE COMPUTERS

Suunto D9tx wristop dive computer is designed to help you get the most out of your
diving.

Suunto D9tx is the world’s first wrist top size dive computer to integrate a tilt-com­pensated 3D digital compass, wireless tank pressure reception, and trimix functions.
It simplifies your diving experience because all the information you need relating to
depth, time, tank pressure, decompression status, and direction is now available on
one easy-to-read screen.

The Suunto D9tx User's Guide contains vitally important information which enables
you to become familiar with your Suunto wristop dive computer. To understand the
use, displays, and limitations of the instrument before using it, please read this user's
guide carefully, and save it for further reference. Note also that a glossary is included
at the back of the user's guide to help you understand dive-specific terminology.

8

2. WARNINGS, CAUTIONS, AND NOTES

Throughout this user's guide, important safety icons are displayed. Three classifications
are used to separate these icons by their order of importance:

WARNING

is used in connection with a procedure or situation that could
result in serious injury or death

CAUTION

is used in connection with a procedure or situation that could
result in damage to the device

NOTE

is used to emphasize important information

Before you go on to read the user's guide itself, it is extremely important that you read
the following warnings. These warnings are intended to maximize your safety while
using Suunto D9tx and must not be ignored.

WARNING

READ THIS user's guide! Carefully read this user's guide in its
entirety, paying close attention to all the warnings listed below,
including Section 5. BEFORE DIVING. Ensure that you fully un­derstand the use, displays and limitations of the dive computer,
because any confusion resulting from neglecting to follow this
user's guide or from improper use of this device could cause you
to commit errors that may lead to serious injury or death.

9

WARNING

NOT FOR PROFESSIONAL USE! Suunto dive computers are
intended for recreational use only. The demands of commercial
or professional diving may expose the diver to depths and condi­tions that tend to increase the risk of decompression illness (DCI).
Therefore, Suunto strongly recommends that the device is not
used for any commercial or professional diving activities.

WARNING

ONLY DIVERS TRAINED IN THE PROPER USE OF SCUBA
DIVING EQUIPMENT SHOULD USE A DIVE COMPUTER! No
dive computer can replace the need for proper dive training. In­sufficient or improper training may cause you to commit errors
that may lead to serious injury or death.

WARNING

THERE IS ALWAYS A RISK OF DECOMPRESSION ILLNESS
(DCI) FOR ANY DIVE PROFILE, EVEN IF YOU FOLLOW THE
DIVE PLAN PRESCRIBED BY DIVE TABLES OR A DIVE
COMPUTER. NO PROCEDURE, DIVE COMPUTER, OR DIVE
TABLE CAN PREVENT THE POSSIBILITY OF DCI OR OXYGEN
TOXICITY! An individual’s physiological make-up can vary from
day to day. The dive computer cannot account for these variations.
You are strongly advised to remain well within the exposure limits
provided by the instrument to minimize the risk of DCI. As an
added precaution, you should consult a physician regarding your
fitness before diving.

10

WARNING

SUUNTO STRONGLY RECOMMENDS THAT SPORT DIVERS
LIMIT THEIR MAXIMUM DEPTH TO 40 M/130 FT OR TO THE
DEPTH CALCULATED BY THE COMPUTER BASED ON THE
SELECTED O2% AND A MAXIMUM PO2OF 1.4 BAR! Exposure
to greater depths increases the risk of oxygen toxicity and decom­pression sickness.

WARNING

DIVES WITH REQUIRED DECOMPRESSION STOPS ARE NOT
RECOMMENDED. YOU SHOULD ASCEND AND BEGIN DE­COMPRESSION IMMEDIATELY WHEN THE DIVE COMPUTER
SHOWS YOU THAT A DECOMPRESSION STOP IS REQUIRED!
Note the blinking ASC TIME symbol and the upward pointing ar­row.

WARNING

USE BACK-UP INSTRUMENTS! Ensure that you use back-up
instrumentation, including a depth gauge, submersible pressure
gauge, timer or watch, and have access to decompression tables
whenever diving with the dive computer.

WARNING

PERFORM PRE-CHECKS! Always activate and check the device
before diving in order to ensure that all Liquid Crystal Display
(LCD) segments are completely displayed, that the device has
not run out of battery power, and that the oxygen, altitude, person­al, and Safety/Deep Stop are correct.

11

WARNING

YOU ARE ADVISED TO AVOID FLYING ANY TIME THE COM­PUTER COUNTS DOWN THE NO-FLY TIME. ALWAYS ACTIV­ATE THE COMPUTER TO CHECK THE REMAINING NO-FLY
TIME PRIOR TO FLYING! Flying or traveling to a higher altitude
within the no-fly time can greatly increase the risk of DCI. Review
the recommendations given by Divers Alert Network (DAN) in
Section 7.4. Flying after diving. There can never be a flying after
diving rule that is guaranteed to completely prevent decompres­sion illness!

WARNING

THE DIVE COMPUTER SHOULD NEVER BE TRADED OR
SHARED BETWEEN USERS WHILE IT IS IN OPERATION! Its
information will not apply to someone who has not been wearing
it throughout a dive, or sequence of repetitive dives. Its dive pro­files must match that of the user. If it is left on the surface during
any dive, the dive computer will give inaccurate information for
subsequent dives. No dive computer can take into account dives
made without the computer. Thus, any diving activity up to four
days prior to initial use of the computer may cause misleading
information and must be avoided.

12

WARNING

DO NOT EXPOSE THE SUUNTO D9tx's OPTIONAL TANK
PRESSURE TRANSMITTER TO ANY GAS MIX CONTAINING
MORE THAN 40% OXYGEN! Enriched air with greater oxygen
content presents a risk of fire or explosion and serious injury or
death.

WARNING

DO NOT DIVE WITH A CYLINDER OF ENRICHED AIR IF YOU
HAVE NOT PERSONALLY VERIFIED ITS CONTENTS AND
ENTERED THE ANALYZED VALUE INTO YOUR DIVE COM­PUTER! Failure to verify cylinder contents and enter the appropri­ate O2% into your dive computer will result in incorrect dive
planning information.

WARNING

THE DIVE COMPUTER WILL NOT ACCEPT FRACTIONAL
PERCENTAGE VALUES OF OXYGEN CONCENTRATION. DO
NOT ROUND UP FRACTIONAL PERCENTAGES! For example,

31.8% oxygen should be entered as 31%. Rounding up will cause
nitrogen percentages to be understated and will affect decompres­sion calculations. If you want to adjust the computer to provide
more conservative calculations, use the personal adjustment
feature to affect decompression calculations, or reduce the PO

2

setting to affect oxygen exposure according to the entered O2%
and PO2 values.

13

WARNING

SET THE CORRECT ALTITUDE ADJUSTMENT SETTING
MODE! When diving at altitudes greater than 300 m/1,000 ft, the
Altitude Adjustment feature must be correctly selected in order
for the computer to calculate the decompression status. The dive
computer is not intended for use at altitudes greater than 3,000
m/10,000 ft. Failure to select the correct Altitude Adjustment set­ting, or diving above the maximum altitude limit will result in erro­neous dive and planning data.

WARNING

SET THE CORRECT PERSONAL ADJUSTMENT SETTING
MODE! Whenever it is believed that factors that tend to increase
the possibility of DCI exist, it is recommended that you use this
option to make the calculations more conservative. Failure to
select the correct Personal Adjustment setting will result in erro­neous dive and planning data.

WARNING

This device contains a Lithium cell battery. To reduce the risk of
fire or burns, do not disassemble, crush, puncture, short external
contacts, or dispose of in fire or water. Replace only with manu­facturer-specified batteries. Recycle or dispose of used batteries
properly.

14

NOTE

It is not possible to change between AIR, MIXED and GAUGE
modes before the instrument has counted down the no-fly time.
There is one exception to this: You can change from AIR to MIXED
mode even during the no-fly time.
When planning both air and nitrox dives during the same dive
series, you should set the instrument in MIXED mode and modify
the gas mix accordingly.
In GAUGE mode the no-fly time is always 48 hours.

15

3. SUUNTO USER INTERFACE

Safety Stop Indicator

No-Fly Icon

Date
Dual Time
Maximum Depth
O

2

/He% (Mixed Mode)
Time
Tank Pressure

Dive Alarm Indicator

Daily Alarm Indicator

Tank pressure bar
graph

Wireless Transmission
Indicator

Low Battery Warning

Present Depth

Current Time Display
Mode Indicator
No-Decompression Time
Total Ascent Time
Ceiling Depth
Remaining Air Time
Safety/Deep Stop Time
Surface Interval Time
No-Fly Time
Compass Display
Tissue Saturation Graph

Diver Attention Symbol

Ascent Rate Bar Graph

Active Water Contact
Indicator

Seconds Display
Stopwatch
Weekday
Dive Time
Temperature
PO

2

% (Mixed Mode)

OLF% (Mixed Mode)

NOTE

If no button is pressed for 5 minutes, the dive computer beeps
and returns to the TIME mode automatically.

16

3.1. Navigating in the menus

Suunto D9tx has four main operating modes - TIME mode (TIME), DIVE mode (DIVE),
PLAN mode (PLAN), and MEMORY mode (MEM). It also has a COMPASS submode,
which can be activated from either TIME or DIVE modes. To toggle between the main
modes, press the MODE button. To select a submode in DIVE and MEM modes, press
the UP/DOWN buttons.

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SETTINGS

Alarm

Time

Dual Time

Date

Units

Backlight

Contrast

Tones

SUB-MODES

Air
Mixed
Gauge

SETTINGS

Gases
Personal/Altitude
Tank Press Pairing

Tank Press Alarm

Depth Alarm

Dive Time Alarm

Sample Rate

Deepstop

Units

TIME DIVE PLAN MEM

SETTINGS

Calibrate

Declination

Timeout

COMPASS

SUB-MODES

Logbook
History

LIGHT LIGHT LIGHT LIGHT

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3.2. Button symbols and functions

The table below explains the main functions of the dive computer's buttons. The buttons
and their use is explained in more detail in the relevant sections of the user's guide.

Table 3.1. Button symbols and functions

Main functionsPressButtonSymbol

Switch between main modes
Switch from submode to main mode
Activate backlight in DIVE mode

ShortMODE

Activate backlight in other modes
Activate stopwatch in DIVE mode

LongMODE

Select a submode
Select and accept settings
Select stopwatch to stop or start in DIVE mode

ShortSELECT

Activate compass in TIME and DIVE modesLongSELECT

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Main functionsPressButtonSymbol

Toggle between alternative displays
Change submode
Increase values

ShortUP

Activate gas switching in MIXED modeLongUP

Toggle between alternative displays
Change submode
Decrease values

ShortDOWN

Enter Setting mode
Toggle between ceiling and remaining air time display

LongDOWN

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4. GETTING STARTED

To get the most out of your Suunto D9tx, use some time to personalize it and really
make it YOUR computer. Set the correct time and date, as well as the alarms and
tones, unit and backlight settings. Then, calibrate and test the compass function.

Suunto D9tx is a very user-friendly dive computer, and you will quickly become famil­iar with its functions. Make absolutely sure that you know your computer and have it
set up as you want it BEFORE getting into the water.

4.1. TIME mode settings

The first thing to do with your Suunto D9tx is to set the TIME mode shortcuts: the time,
alarm, dual time, date, units, backlight, contrast, and tones.

The figure below shows how to toggle between different shortcuts in the TIME mode:

NOTE

The seconds display reverts to date display after 5 minutes in
order to save battery power.

NOTE

The display is illuminated by holding down the MODE button for
more than 2 seconds.

21

Now that after you know how to toggle between the shortcuts, you can start to set
them.

The figure below shows how to enter the TIME Settings menu.

USE UP AND DOWN BUTTONS

TO TOGGLE BETWEEN ALARM, TIME,

DUAL TIME, DATE, UNITS, CONTRAST

AND TONES.

4.1.1. Setting the alarm

The dive computer has a daily alarm function. When the daily alarm activates, the
screen blinks and the alarm sounds for 60 seconds. Press any button to stop the
alarm.

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ADJUST WITH UP AND

DOWN BUTTONS. ACCEPT

WITH SELECT BUTTON.

4.1.2. Setting the time

In the Time setting mode, you are able to set the hour, minute, and second, as well
as choose between a 12 and 24 hour display.

ADJUST WITH UP AND

DOWN BUTTONS. ACCEPT

WITH SELECT BUTTON.

4.1.3. Setting the dual time

In the Dual Time setting mode, you are able to select the hour and minute of a dual
time, which is useful when traveling to a different time zone.

23

ADJUST WITH UP AND
DO WN BUTTONS. ACCEPT
WITH SELECT BUTTON.

4.1.4. Setting the date

In the Date setting mode, you are able to set the year, month, and day. The day of
the week is automatically calculated in accordance with the date. In metric units the
date is presented as DD/MM, and in imperial units as MM/DD.

ADJUST WITH UP AND
DOWN BUTTONS. ACCEPT

WITH SELECT BUTTON.

4.1.5. Setting the units

In the Units setting mode, you are able to choose whether the units are displayed in
either the metric or imperial system (meters/feet, Celsius/Fahrenheit, and so on).

24

ADJUST WITH UP AND
DOWN BUTTONS. ACCEPT
WITH SELECT BUTTON.

4.1.6. Setting the backlight

In the Backlight setting mode, you are able to turn the backlight ON or OFF and to
define how long it stays on for (5, 10, 20, 30, or 60 seconds). When the backlight is
turned OFF, it does not illuminate when an alarm sounds.

ADJUST WITH UP AND
DOWN BUTTONS. ACCEPT
WITH SELECT BUTTON.

4.1.7. Setting the contrast

In the Contrast setting mode, you are able to set the contrast of the display (the value
range is between 0 and 10).

25

ADJUST WITH UP AND
DOWN BUTTONS. ACCEPT

WITH SELECT BUTTON.

4.1.8. Setting the tones

In the Tones setting mode, you are able to activate or deactivate the tones.

ADJUST WITH UP AND
DOWN BUTTONS. ACCEPT

WITH SELECT BUTTON.

NOTE

When the tones are off, there are no audible alarms.

4.2. Stopwatch

The Stopwatch function in Suunto D9tx measures elapsed and split times.
A separate stopwatch (dive timer) can also be used in the DIVE mode. For more in-

formation, refer to Section 6.1.6. Stopwatch (Timer).

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USE DOWN BUTTON TO START

STOPWATCH AND TAKE A SPLIT TIME.

THE UP BUTTON STOPS THE STOPWATCH

AND LONG PRESSING IT RESETS IT.

4.3. AC water contacts

The water and data transfer contact is located on the side of the case. When sub­merged, the water contact poles are connected by the conductivity of the water and
the “AC” symbol appears on the display. The AC text is shown until the water contact
deactivates.

AC APPEARS IN THE TOP RIGHT

CORNER OF THE DISPLAY, WHEN THE DIVE

COMPUTER IS IN CONTACT WITH WATER.

THIS ALSO ACTIVATES THE DIVE MODE.

27

Contamination or dirt on the water contact may prevent this automatic activation.
Therefore, it is important that the water contact is kept clean. The contact can be
cleaned with fresh water and a soft brush, for example a tooth brush.

NOTE

Water or moisture build-up around the water contact may cause
the contact to activate automatically. This can happen, for ex­ample, when washing your hands or sweating. If the water contact
activates in the TIME mode, the AC symbol will appear on the
display, and will be shown until the water contact deactivates. To
save battery power, you should deactivate the water contact by
cleaning it and/or drying it with a soft towel.

4.4. Learning how to use your compass

Suunto D9tx is the first dive computer in the world to integrate a digital compass. It
can be used both while diving and on the surface, and can be accessed by long­pressing the SELECT button.

28

IF ACCESSED FROM TIME MODE,

TIME AND BEARING ARE DISPLAYED

AT THE BOTTOM OF THE SCREEN.

ACCESSED FROM DIVE MODE,
CURRENT DEPTH, AND TIME OR
MAXIMUM DEPTH, TANK PRESSURE,
AS WELL AS BEARING OR DIVE TIME

OR TEMPERATURE ARE DISPLAYED.

NOTE

When accessed from DIVE mode, toggle between the alternative
displays by pressing the UP/DOWN buttons.

4.4.1. Compass display

The Suunto D9tx displays the compass as a graphical representation of a compass
rose. The rose displays the cardinal and half cardinal points, in addition to which, the
current bearing is also displayed numerically.

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4.4.2. Locking a bearing

A bearing can be locked to help you follow a selected course, and directional arrows
point towards the locked bearing. The last locked bearing is stored and is available
the next time the compass is activated. In the DIVE mode the locked bearings are
also stored in the log.

TO LOCK A BEARING,

PRESS SELECT.

The Suunto D9tx also provides help for navigating square and triangular patterns, as
well as navigating a return heading. This is made possible by following graphical
symbols in the center of the compass display:

Table 4.1. Locked bearing symbols

ExplanationSymbol

You are traveling towards the locked bearing

You are 90 (or 270) degrees from the locked bearing

30

ExplanationSymbol

You are 180 degrees from the locked bearing

You are 120 (or 240) degrees from the locked bearing

4.4.3. Compass settings

You can define the compass settings (Calibration, Declination and Timeout) in the
COMPASS mode:

Calibration

Because of changes in the surrounding magnetic field, the Suunto D9tx electronic
compass occasionally needs to be re-calibrated. During the calibration process, the
compass adjusts itself to the surrounding magnetic field . As a basic rule, you should
calibrate the compass whenever it does not seem to operate properly, or after replacing
the dive computer's battery.

31

Strong electromagnetic fields, such as power lines, stereo speakers, and magnets
can affect the compass calibration. Therefore, it is advisable to calibrate the compass
if your Suunto D9tx has been exposed to these fields.

NOTE

When traveling overseas, it is recommended that you recalibrate
the compass at the new location before using it.

NOTE

Remember to hold the Suunto D9tx level during the calibration
process.

32

To calibrate the compass:

HOLD THE

DEVICE LEVEL
AND SLOWLY
ROTATE 360°.

THEN SLOWLY
TURN THE DEVICE
90° TO VERTICAL

POSITION.

If the calibration fails several times in a row, it is possible that you are in an area with
sources of magnetism, such as large metal objects, power lines or electric appliances.
Move to another location and try to calibrate the compass again. If the calibration
continues to fail, contact an authorized Suunto service center.

Declination

You can compensate for the difference between true north and magnetic north by
adjusting the compass declination. The declination can be found, for example, from
sea charts or topographic maps of the local area.

33

ADJUST WITH UP

AND DOWN. ACCEPT

WITH SELECT.

Time-out

You can set the compass time-out minutes. After the set time has passed from the
latest button press, the dive computer returns to the TIME or DIVE mode from the
COMPASS mode.

ADJUST WITH UP

AND DOWN. ACCEPT

WITH SELECT.

You can exit the COMPASS mode also by long pressing the SELECT button.

34

5. BEFORE DIVING

Do not attempt to use the dive computer without reading this user's guide in its entirety,
including all the warnings. Make sure that you fully understand the use, displays and
limitations of the instrument. If you have any questions about the manual or the dive
computer, contact your SUUNTO dealer before diving with the dive computer.

Always remember that YOU ARE RESPONSIBLE FOR YOUR OWN SAFETY!
When used properly, Suunto D9tx is an outstanding tool for assisting properly trained,

certified divers in planning and executing sport dives. It is NOT A SUBSTITUTE FOR
CERTIFIED SCUBA INSTRUCTION, including training in the principles of decompres­sion.

WARNING

Diving with gas mixtures exposes you to risks that are different
from those associated with diving with standard air. These risks
are not obvious, and require training to understand and avoid.
Risks include possible serious injury or death.

Do not attempt to dive with any gas mix other than standard air without first receiving
certified training in this specialty.

5.1. The Suunto Technical RGBM

Suunto’s Technical RGBM, utilized in the Suunto D9tx, predicts both dissolved and
free gas in the blood and tissues of divers. It is a significant advance on the classic
Haldane models, which do not predict free gas. The advantage of Suunto RGBM is
additional safety through its ability to adapt to a variety of situations and dive profiles.

35

In order to optimize the response to different increased risk situations, an additional
category of stop, referred to as a Mandatory Safety Stop, has been introduced. The
combination of stop types depends on the user settings and the specific dive situation.

To get the most from the RGBM safety benefits, refer to Section 5.8.8. Setting the
deep stops and Section 5.11. Deep stops.

5.2. Emergency ascents

Before you dive, you must have the dive plan created with the Suunto Dive Planner
printed out on a slate. You must also have a back-up plan for lost gases. In the unlikely
event that the dive computer malfunctions during a dive, start using an alternative
depth gauge and timer and following the ascent schedule and gas switches that are
on the slate. If you dive using only air, follow these steps:

1.

Assess the situation calmly and then move promptly to less than 18 m/60 ft.

2.

At 18 m/60 ft, slow down your ascent rate to 10 m/33 ft per minute and move to
a depth between 3 and 6 m/10 and 20 ft.

3.

Stay there for as long as your air supply will safely allow. After reaching the sur­face, do not dive for at least 24 hours.

5.3. Dive computer limitations

While the dive computer is based on current decompression research and technology,
you must realize that the computer cannot monitor the actual physiological functions
of an individual diver. All decompression schedules currently known to the authors,
including the U.S. Navy Tables, are based on theoretical mathematical models, which
are intended to serve as a guide to reduce the probability of decompression illness.

36

5.4. Mixed gas diving

Diving with nitrox provides you with an opportunity to increase bottom times or reduce
the risk of decompression illness by reducing the nitrogen content in the gas mix.

Diving with gas mixes provides you with an opportunity to increase bottom times,
shorten decompression times, decrease the oxygen partial pressure at depth, and
reduce the risk of nitrogen narcosis or decompression illness by reducing the nitrogen
content in the gas mix.

However, when the gas mix is altered or depth increased, the oxygen partial pressure
is generally increased. This increase exposes the diver to an oxygen toxicity risk not
usually considered in recreational diving. In order to manage this risk, the dive computer
tracks the time and intensity of the oxygen exposure and provides the diver with in­formation to adjust the dive plan in order to maintain oxygen exposure within reasonably
safe limits.

In addition to the physiological effects of enriched air on the body, there are operational
considerations to be addressed when handling altered breathing mixes. Elevated
concentrations of oxygen present a fire or explosion hazard. Consult the manufacturer
of your equipment to check its compatibility with nitrox.

5.5. Audible and visual alarms

The dive computer has audible and visual alarms that advise when important limits
are approached or that prompt you to acknowledge preset alarms. The table below
describes the different alarms and their meanings.

37

Table 5.1. Dive computer alarms

DurationSound patternAlarm type

2.4 s sound + 2.4 s breakHigh priority

0.8 s sound + 3.2 s break

Low priority

Table 5.2.

InterpretationSound patternInstructional beep

Start ascending

Ascending

Start descendingDescending

Change gasDescending-

ascending

The visual information on the dive computer display is shown during the alarm breaks
in order to save battery.

38

Table 5.3. Audible and visual alarm types

Alarm reasonAlarm type

PO2 value is greater than the adjusted value. Current
depth is too deep for the gas in use. You should imme­diately ascend or change to a gas with a lower oxygen
percentage.

High priority alarm followed
by "Start ascending" beep,
repeated for the maximum of
three minutes. The PO2 value
blinks.

PO2 value is smaller than 0.18 bar. In DIVE Mixed
mode only. The depth is too shallow and the ambient
pressure is too low for the current gas. The oxygen
content is too low to keep you conscious. You should
immediately switch the gas.

High priority alarm followed
by "Change gas" beep, soun­ded two times. The PO2
value blinks.

Decompression ceiling depth is exceeded. You should
immediately descend to, or below, the ceiling

High priority alarm followed
by "Start descending" beep,
repeated for the maximum of
three minutes. The Er symbol
blinks and an arrow points
downwards.

Maximum allowed ascent rate, 10 m per min / 33 ft per
min, is exceeded. Slow the ascend rate down.

High priority alarm, sounded
three times. The SLOW sym­bol blinks.

39

Alarm reasonAlarm type

No-decompression dive turns into a decompression
stop dive. Depth is below the decompression floor
level. You should ascend to, or above, the floor.

Low priority alarm followed by
"Start ascending" beep,
sounded two times. The ASC
TIME symbol blinks and an
arrow points upwards.

Gas change is recommended. In DIVE Mixed mode
only. You should change to a gas more favorable to
decompression. ASC TIME assumes that the gas is
changed and is accurate only if you change the gas
accordingly.

Low priority alarm followed by
"Change gas" beep, sounded
once. The Gas mix value
(O2%, O2%|He%) blinks.

Mandatory Deep Stop is violated. You should descend
to complete the Deep Stop.

Low priority alarm followed by
"Start descending" beep, for
the duration of the Deep Stop
violation. The DEEPSTOP
symbol blinks and an arrow
points downwards.

The Deep Stop depth is reached. Make the Mandatory
Deep Stop for the duration shown by the timer.

Low priority alarm followed by
two short beeps, sounded
once. The DEEPSTOP and
timer symbols are displayed.

40

Alarm reasonAlarm type

Cylinder pressure reaches the selected alarm pressure,
10 - 200 bar. Cylinder pressure reaches the fixed alarm
pressure, 50 bar. This alarm operates only if the pairing
to the wireless tank pressure transmitter is performed
correctly and the transmission of tank pressure data
is not disrupted during the dive for any reason. You
can acknowledge the alarm.

Low priority alarm, sounded
two times. The Tank pres-
sure symbol blinks.

The OLF value reaches the fixed 80% or 100%. In the
DIVE Mixed mode only. You can acknowledge the
alarm.

Low priority alarm, sounded
two times. The OLF% value
blinks if the PO2 value is
greater than 0.5 bar.

The selected depth (3–120 m / 10–394 ft) is exceeded.
The fixed maximum depth (120 m / 394 ft) is exceeded.
You can acknowledge the alarm.

Low priority alarm, sounded
two times. The Maximum
depth value blinks.

The selected dive time (1–999 min) is exceeded. You
can acknowledge the alarm. .

Low priority alarm, sounded
two times. The Dive time
value blinks.

NOTE

When the backlight is turned OFF, it does not illuminate when an
alarm is activated.

41

NOTE

When the tones are turned OFF, the alarms are not sounded
when an alarm is activated.

WARNING

WHEN THE OXYGEN LIMIT FRACTION INDICATES THAT THE
MAXIMUM LIMIT IS REACHED, YOU MUST IMMEDIATELY
TAKE ACTION TO REDUCE OXYGEN EXPOSURE. Failure to
take action to reduce oxygen exposure after the warning is given
can rapidly increase the risk of oxygen toxicity, injury, or death.

5.6. Error conditions

The dive computer has warning indicators that alert you to react to certain situations
that would significantly increase the risk of DCI. If you do not respond to its warnings,
the dive computer will enter an Error mode, indicating that the risk of DCI has greatly
increased. If you understand the dive computer and operate it sensibly, it is very unlikely
you will ever put the instrument into the Error mode.

Descent at the rate of 10 m/min is included in the time. The times allow for a safe ascent
using the bottom gas all the way to the surface without exceeding tissue pressures.

Omitted decompression

The Error mode results from omitted decompression, for example, when you stay
above the ceiling for more than three minutes. During this three-minute period the Er
warning is shown and the audible alarm beeps. After this, the dive computer enters a
permanent Error mode. The instrument will continue to function normally if you descend
below the ceiling within this three-minute period.

42

When the dive computer is in the permanent Error mode, only the Er warning is shown
in the center window. The dive computer does not show times for ascent or stops.
However, all the other displays function as before to provide information for ascent.
You must immediately ascend to a depth of 3 to 6 m/10 to 20 ft and remain at this
depth until air supply limitations require you to surface.

After surfacing, you should not dive for a minimum of 48 hours. During the permanent
Error mode, the Er text is displayed in the center window and the planning mode is
disabled.

5.7. Wireless transmission

In order to use the transmitter, the wireless integration needs to be enabled in your
Suunto D9tx settings. To enable or disable the wireless integration, refer to Sec-
tion 5.8.3. Setting the tank pressure pairing.

5.7.1. Installing the wireless transmitter

When purchasing the Suunto D9tx, we strongly recommend that you have your Suunto
representative attach the transmitter to the first stage of your regulator.

However, if you decide to attach it yourself, do the following:

1.

Remove the high pressure (HP) port plug on the first stage of your regulator using
an appropriate tool.

2.

Thread the high pressure transmitter of the Suunto D9tx into the HP port of your
regulator with your fingers. DO NOT OVERTIGHTEN! Maximum torque is 6 Nm/4.4
lbsft or 53 lbsin. The seal is based on a static O-ring, not force!

43

3.

Attach the regulator to the scuba cylinder and slowly open the valve. Check for
leaks by submerging the regulator first stage in water. If leaks are detected, check
the condition of the O-ring and sealing surfaces.

5.7.2. Pairing and code selection

In order to receive wireless data, the transmitter and the Suunto D9tx need to be
paired. During the pairing procedure, the dive computer locks on the code that the
transmitter has.

The transmitter is activated when the pressure exceeds 15 bar/300 psi and it then
starts sending pressure data together with a code number. During the pairing procedure,
the Suunto dive computer stores the code number and starts displaying pressure
values that are received with that code. This coding procedure prevents data mix-up
from other divers also using a Suunto wireless transmitter.

When there is no stored code, the Suunto D9tx displays “cd:--” and receives data with
lowered sensitivity from a very short distance only. By taking the Suunto D9tx unit
close to the transmitter, it will store the received code and start receiving with full
sensitivity and display data received with this code only. The code is stored for approx­imately two hours, or until the cylinder pressure falls below 10 bar/145 psi. The set
code can also be manually erased.

NOTE

The pairing procedure only needs to be performed once, before
the first use. You do not need to redo the pairing unless you
change the transmitter to a new one, or another diver in your
group uses the same code as you.

To pair the transmitter and the Suunto D9tx dive computer:

44

1.

Ensure that the transmitter is properly attached to the regulator’s HP port and
that the regulator is properly attached to the cylinder.

2.

Ensure that the Suunto D9tx is turned on, and that the wireless integration is en­abled in the Suunto D9tx settings (Tank Press is set ON. For more information,
refer to Section 5.8.3. Setting the tank pressure pairing). If the Suunto D9tx is in
the TIME mode, enter the DIVE mode by short-pressing the MODE button. The
D9tx should display “cd:--” in the lower left corner of the display.

3.

Slowly open the cylinder valve fully and pressurize the system. The transmitter
starts transmitting when the pressure exceeds 15 bar/300 psi.

4.

Take the Suunto D9tx unit close to the transmitter. The unit will then quickly display
the selected code number and then start displaying the transmitted cylinder
pressure. The wireless transmitter indicator (flash symbol) is displayed every time
the Suunto D9tx receives a valid signal.

WARNING

If there are several divers using Suunto D9tx with wireless trans­mission, always ensure that each diver is using a different code
before starting the dive. In case there are several divers using
the same code, the transmitter's code must be changed before
diving.

To assign a new transmitter code:

1.

Slowly open the cylinder valve fully to pressurize the system.

2.

Close the valve. Depressurize the regulator so that the pressure is reduced to
less than 10 bar/145 psi. Wait about 10 seconds, and slowly open the cylinder
valve again to re-pressurize to above 15 bar/300 psi.

The transmitter assigns a new code automatically.

45

NOTE

To pair on the new transmitter code, the Suunto D9tx code must
be cleared first.

To re-pair the transmitter with the new code and the Suunto D9tx dive computer:

1.

In the DIVE mode of the Suunto D9tx , long-press the DOWN button to enter the
DIVE settings. Enter the Tank Press Pairing menu (Refer to Section 5.8.3. Setting
the tank pressure pairing). Short-press the SELECT button to bypass the tank
pressure ON/OFF selection (the tank pressure transmission must remain ON).

2.

In the next menu, a Code number is displayed. Clear the code by short-pressing
the UP button (toggle from “Ok” to “Clear”), and press the SELECT button.

3.

Short-press the MODE button to exit the DIVE settings.

4.

Take the Suunto D9tx unit close to the transmitter (the system must be pressurized
to above 15bar/300 psi). The dive computer displays the received new code
number and then start displaying the transmitted cylinder pressure. The wireless
transmitter indicator (flash symbol) is displayed every time the Suunto D9tx re­ceives a valid signal.

NOTE

In order to save battery energy, the transmitter enters power
saving mode with slower data transmission rate if the tank pres­sure remains unchanged for more than five (5) minutes. The
transmitter continues transmitting with the saved code when any
pressure change is measured.

46

5.7.3. Transmitting data

After the pairing procedure, the Suunto D9tx will receive cylinder pressure data from
the transmitter. The pressure is displayed in either bars or psi, depending on the unit
selected. Any time the Suunto D9tx receives an appropriate signal, a flash symbol is
displayed in the lower left corner.

Table 5.4. Pressure transmission related displays

FigureIndicationDisplay

A

Set Code. No code stored, Suunto D9tx ready for pairing with
transmitter.

Cd:--

B

Set Code. Code number can be between 01–32.

Cd:10

C

Pressure reading over 360 bar/5220 psi.

- - -

D

Pressure reading has not been updated for more than one minute.
The latest valid pressure reading is displayed intermittently.

Transmitter is out of range, in power saving mode or on another
channel. Activate the transmitter by breathing off the regulator,
and assign a new code to the Suunto D9tx unit if necessary.

no conn

E

Pressure transmitter battery voltage is low. The pressure reading
is displayed intermittently. Change the transmitter battery!

batt

47

A B C D E

5.8. DIVE mode settings

Suunto D9tx has several user-definable functions, as well as depth and time-related
alarms that you can set according to your personal preferences. The DIVE mode
settings are dependent on the dive submode chosen (AIR, MIXED, GAUGE), so that,
for example, trimix settings are only available in the MIXED submode.

The table below shows what DIVE settings are available in each DIVE submode.

Table 5.5. DIVE mode settings

GAUGE modeMIXED modeAIR modeSetting

XMixed gas

XXPersonal/Altitude

XXXTank pressure pairing

XXXTank pressure alarm

XXXDepth alarm

48

GAUGE modeMIXED modeAIR modeSetting

XXXDive time alarm

XXXSample rate

XDeep stop

XXXUnits

The figure below shows how to enter the DIVE mode settings menu.

USE UP AND
DOWN BUTTONS TO
TOGGLE BETWEEN

DIVE SETTINGS.

NOTE

Some settings cannot be changed until five (5) minutes has
elapsed after the dive.

49

5.8.1. Setting the gases

If set to the MIXED mode, the correct oxygen and helium percentages of the gas in
your cylinders (and additional gases) must always be entered into the dive computer
to ensure correct tissue and oxygen calculation. In addition, the oxygen partial pressure
limit must be set. You can either modify the dive plan with the Suunto Dive Planner
or enter the correct values directly into the dive computer after analyzing the gas mixes
in your cylinders.

When in the MIXED setting mode, the equivalent maximum operating depth, based
on the chosen setting, is also be displayed.

After entering values for Mix1, you can set additional mixes, Mix2–Mix8, similarly. You
can set them to "PRIMARY", "SECONDARY" or "OFF". Mix1 is always set as a primary
gas.

In order to minimize the risk of error during a dive, it is highly recommended that the
mixes are set in the proper order. This means that as the mix number rises, so does
oxygen content, and this is the order they are usually used during the dive. Before a
dive, only enable the mixes you actually have available and remember to check the
set values to ensure they are correct.

50

The ASC time is calculated based on the assumption that you start the ascent profile
immediately and all the PRIMARY gases are changed as soon as their maximum op­erating depth allows it. That is, using the gases that are set as primary, the most op­timal ascent schedule for the moment is calculated.

To see the most pessimistic ascent schedule, that is, a schedule for the situation when
gases are not changed at all, you can set the gases as secondary and the time it takes
to finish the decompression using the current breathing gas is shown as the ASC time.

Showing the most pessimistic ascent schedule during a long dive can easily result in
the ascent time no longer fitting the reserved field and the dive computer displays "--

-" (max. 199 min).

NOTE

While setting the gases, notice that the calculated maximum op­erating depth is displayed in the upper field. You cannot change
to this gas before you have ascended above this depth.

In MIXED mode, the default oxygen percentage (O2%) setting is 21% (air) and oxygen
partial pressure (PO2) setting 1.4 bar.

5.8.2. Setting the personal/altitude adjustments

The current Altitude and Personal Adjustment settings are displayed in the startup
screen when entering the DIVE mode. If the mode does not match the altitude or
personal conditions (refer to Section 5.9.4. Diving at altitude and Section 5.9.5. Per-
sonal adjustments), it is imperative that you enter the correct selection before diving.
Use Altitude Adjustment to select the correct altitude and use Personal Adjustment to
add an extra level of conservatism.

51

ADJUST WITH UP AND
DOWN BUTTONS. ACCEPT
WITH SELECT BUTTON.

5.8.3. Setting the tank pressure pairing

In the Tank Pressure Pairing setting mode, the wireless transmission can be set “ON”
or “OFF” depending on whether the wireless pressure transmitter is used or not. When
the wireless transmission is set “OFF”, no cylinder pressure-related data is shown,
nor data reception made. The Code setting allows you to verify the selected transmitter
code and to clear the stored transmitter code. Clearing the code enables re-pairing
with the transmitter, which can be necessary if a new transmitter or used, or if several
divers are using the same transmitter code.

ADJUST WITH UP AND
DOWN BUTTONS. ACCEPT
WITH SELECT BUTTON.

52

5.8.4. Setting the tank pressure alarm

The tank pressure alarm can be set "ON" or "OFF" and in the range of 10–200 bar.
The alarm is the secondary cylinder pressure alarm point. The alarm is activated when
the tank pressure drops below the set limit. You can acknowledge this alarm.

The 50 bar/700 psi alarm, however, is fixed and cannot be changed. You cannot ac­knowledge this alarm.

TANK PRESSURE HAS DROPPED BELOW 50 BAR

AND THE REMAINING AIR TIME IS 4 MINUTES. THE

DISPLAY BLINKS AND THERE IS AN AUDIBLE ALARM.

5.8.5. Setting the depth alarm

The Depth Alarm setting is factory-set to 30 m/100 ft, but you can adjust it according
to your personal preference, or switch it off altogether. The depth range can be set
from 3 m to 120 m/10 ft to 394 ft.

ADJUST WITH UP AND

DOWN BUTTONS. ACCEPT

WITH SELECT BUTTON.

53

5.8.6. Setting the dive-time alarm

The Dive Time Alarm setting can be activated and used for several purposes to add
to your diving safety.

ADJUST WITH UP AND

DOWN BUTTONS. ACCEPT

WITH SELECT BUTTON.

NOTE

With a range of 1–999 minutes, the alarm can be set to your
planned bottom time, for example.

5.8.7. Setting the sample rate

The Sample Rate setting controls how often the depth, tank pressure (if enabled), and
water temperature is stored in the memory.

You can set the dive profile sample rate to 10, 20, 30, or 60 seconds. The factory default
setting is 20 seconds.

ADJUST WITH UP AND

DOWN BUTTONS. ACCEPT

WITH SELECT BUTTON.

54

5.8.8. Setting the deep stops

In the AIR mode in the Deep Stops setting mode, the Deep stops can be set “ON” or
“OFF” depending on whether the Deep stops are used or not. In the MIXED mode the
Deep stops are always set ON.

ADJUST WITH UP AND

DOWN BUTTONS. ACCEPT

WITH SELECT BUTTON.

5.8.9. Setting the units

In the Unit settings you are able to choose between metric (meters/Celsius/bar) and
imperial (feet/Fahrenheit/psi) units.

ADJUST WITH UP AND

DOWN BUTTONS. ACCEPT

WITH SELECT BUTTON.

5.9. Activation and pre-checks

This section describes how to activate the DIVE mode and explains the pre-checks
that it is highly recommended you perform before you get into the water.

55

5.9.1. Accessing DIVE mode

The Suunto D9tx has three diving modes: AIR mode for diving with standard air only,
MIXED mode for diving with oxygen enriched mixtures, and GAUGE mode for use as
a bottom timer and for freediving.

The chosen dive mode is displayed when the DIVE mode is accessed, and you can
toggle between the submodes by pressing the UP/DOWN buttons.

5.9.2. DIVE mode activation

The dive computer activates automatically when submerged deeper than 0.5 m/1.5
ft. However, it is necessary to activate the DIVE mode BEFORE diving to check

the cylinder pressure, altitude and personal adjustment settings, battery condi­tion, oxygen settings , and so on.

After activation, all graphical display elements are turned ON, and the backlight and
the beep are activated. After this, the selected altitude and personal settings are dis­played O2% and the PO2 values. A few seconds later the battery power indicator is
shown, as well as the maximum operating depth (MOD, 66.2 m), O2% (21%) and PO2
(1.6) value. A few seconds later the battery power indicator is shown.

56

WARNING

SUUNTO STRONGLY RECOMMENDS THAT SPORT DIVERS
LIMIT THEIR MAXIMUM DEPTH TO 40 M/130 FT! Exposure to
greater depths increases the risk of oxygen toxicity and decom­pression sickness.

At this time, perform your pre-checks, and ensure that:

•

the instrument operates in the correct mode and provides a complete display
(AIR/MIXED/GAUGE mode)

•

the battery level is ok

•

the altitude, personal adjustment, Deep stops settings are correct

•

the instrument displays correct units of measurement (Metric/Imperial)

•

the instrument displays the correct temperature and depth (0.0 m/0 ft)

•

the alarm beeps

If the optional wireless pressure transmitter is used ensure that:

•

the pressure transmitter has been properly attached and the cylinder valve is open

•

the transmitter and the wrist unit have been properly paired on a suitable code

•

the pressure transmitter is working (lightning symbol blinks, cylinder pressure is
displayed), and that there is no low battery warning displayed

57

•

you have enough air for your planned dive. You should also check the pressure
reading against your back-up pressure gauge

And, if set to MIXED mode, ensure that:

•

the correct number of mixes is set and that the oxygen percentages are adjusted
according to the measured blends in your cylinders

•

the oxygen partial pressure limits are set correctly

For more information on the MIXED mode, please refer to Section 6.2. Diving in the
MIXED mode .

The dive computer is now ready for diving.

5.9.3. Battery power indication

Temperature or internal oxidation of the battery affect the battery voltage. If the instru­ment is stored for a long period, or used in cold temperatures, the low battery warning
may be displayed even though the battery has enough capacity. In these cases, re­enter DIVE mode to receive the battery power indication.

After the battery check, the low battery warning is indicated by the battery symbol.

58

If the battery symbol is displayed in the Surface mode, or if the display is faded or
weak, the battery may be too low to operate the dive computer, and battery replacement
is recommended.

NOTE

For safety reasons, the backlight cannot be activated when the
low battery warning is indicated by the battery symbol.

The optional wireless pressure transmitter sends out a low battery (batt) warning when
its battery voltage is getting low. This is shown intermittently instead of the pressure
reading. When you get this warning, the pressure transmitter's battery needs to be
replaced.

5.9.4. Diving at altitude

The dive computer can be adjusted both for diving at altitude and also to increase the
conservatism of the mathematical nitrogen model.

When programming the instrument for the correct altitude, you need to select the
correct Altitude Adjustment settings according to Table 5.6, Altitude Adjustment settings.
The dive computer will adjust its mathematical model according to the entered altitude
setting, giving shorter no-decompression times at higher altitudes (refer to Sec-
tion 10.2.3. Altitude diving).

Table 5.6. Altitude Adjustment settings

Altitude rangeAlt. adjustment value

0–300 m / 0–1000 ftA0

300–1500 m / 1000–5000 ftA1

59

Altitude rangeAlt. adjustment value

1500–3000 m / 5000–10 000 ftA2

NOTE

Section 5.8.2. Setting the personal/altitude adjustments describes
how the Altitude value is set.

WARNING

Traveling to a higher elevation can temporarily cause a change
in the equilibrium of dissolved nitrogen in the body. It is recom­mended that you acclimatize to the new altitude by waiting at
least three (3) hours before diving.

5.9.5. Personal adjustments

There are personal factors that can affect your susceptibility to DCI, which you can
predict in advance, and input into the decompression model. Such factors vary between
divers and also for the same diver from one day to another. The five-step Personal
Adjustment setting is available if a more conservative or aggressive dive plan is desired.

The personal factors which tend to increase the possibility of DCI include, but are not
limited to:

•

cold exposure —water temperature less than 20 °C/68 °F

•

below average physical fitness level

•

fatigue

•

dehydration

•

personal settings in air/ean

60

•

previous history of DCI

•

stress

•

obesity

•

patent foramen ovale (PFO)

•

exercise on or after dive

This feature is used to adjust the computer to be more conservative, according to
personal preference, by entering the suitable Personal Adjustment setting with the
help of Table 5.7, Personal Adjustment settings. In ideal conditions, retain the default
setting, P0. If conditions are more difficult, or any of the factors which tend to increase
the possibility of DCI exist, select P1, or even the most conservative P2. For very ex­perienced divers willing to take high personal risks and full responsibility of their own
condition, two negative values of the personal adjustments, P-2 and P-1, exist.The
dive computer then adjusts its mathematical model according to the entered Personal
Adjustment setting, giving shorter no-decompression times.

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Table 5.7. Personal Adjustment settings

Desired tablesCondition

Personal ad­justment value

Progressively less conservativeIdeal conditions, excellent physical
fitness, highly experienced with a
lot of dives in the near past

P-2

Ideal conditions, good physical fit­ness, well experienced with dives
in the near past

P-1

DefaultIdeal conditionsP0

Progressively more conservativeSome risk factors or conditions
exist

P1

Several risk factors or conditions
exist

P2

WARNING

Personal adjustment setting P0–P-2 causes a high risk of DCI,
or other personal injury, and death.

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5.10. Safety Stops

Safety Stops are widely considered good diving practice for recreational diving, and
are an integral part of most dive tables. The reasons for performing a Safety Stop in­clude: reducing sub-clinical DCI, microbubble reduction, ascent control, and orientation
before surfacing.

The Suunto D9tx displays two different types of Safety Stops: Recommended Safety
Stop and Mandatory Safety Stop.

5.10.1. Recommended Safety Stops

With every dive over 10 meters, there is a three-minute countdown for the Recommen­ded Safety Stop, to be taken in the 3–6 m/10–20 ft range. This is shown with the STOP
sign and a three-minute countdown in the center window instead of the no-decompres­sion time.

WHEN STOP IS DISPLAYED,

MAKE A RECOMMENDED SAFETY

STOP FOR 3 MINUTES.

NOTE

The Recommended Safety Stop, as the name implies, is recom­mended. If it is ignored, there is no penalty applied to the following
surface intervals and dives.

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5.10.2. Mandatory Safety Stops

When the ascent rate exceeds 10 m/33 ft per minute continuously for more than five
(5) seconds, the microbubble build-up is predicted to be more than is allowed for in
the decompression model. The Suunto RGBM calculation model responds to this by
adding a Mandatory Safety Stop to the dive. The time of this Mandatory Safety Stop
depends on the severity of the ascent rate excess.

The STOP sign is shown in the display and when you reach the depth zone between
6 m and 3 m/20 ft and 10 ft, the CEILING label, ceiling depth, and the calculated Safety
Stop time also appear in the display. Wait until the Mandatory Safety Stop warning
disappears. The total length of the Mandatory Safety Stop time depends on the seri­ousness of the ascent rate violation.

WHEN CEILING AND STOP ARE

DISPLAYED, MAKE A ONE MINUTE

MANDATORY SAFETY STOP IN THE

DEPTH ZONE BETWEEN 6 M AND 3 M.

You must not ascend shallower than 3 m/10 ft with the Mandatory Safety Stop warning
on. If you ascend above the Mandatory Safety Stop ceiling, a downward pointing arrow
will appear and a continuous beeping starts. You should immediately descend to, or
below, the Mandatory Safety Stop ceiling depth. If you correct this situation at any
time during the dive, there are no effects on the decompression calculations for future
dives.

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WHEN CEILING AND STOP ARE DISPLAYED
WITH DOWNWARD POINTING ARROW,
IMMEDIATELY (WITHIN 3 MINUTES) DESCEND

TO OR BELOW CEILING.

If you continue to violate the Mandatory Safety Stop, the tissue calculation model is
affected and the dive computer shortens the available no-decompression time for your
next dive. In this situation, it is recommended that you prolong your surface interval
time before your next dive.

5.11. Deep stops

The Suunto RGBM model calculates deep stops iteratively, placing the first stop about
halfway between the maximum depth and the ceiling depth. After the first Deep stop
is completed, another Deep stop will be prompted halfway to the ceiling, and so on
until the ceiling depth is reached.

DURING DESCENT,
YOU'RE SHOWN THAT A
DEEPSTOP IS NEEDED AT

THE DEPTH OF 16 M.

DURING ASCENT, YOU'RE
ADVICED TO MAKE A DEEP
STOP AT 16 M FOR THE
DURATION SHOW BY THE

TIMER (42 S REMAINING).

Enabling the deep stops does not disable Recommended Safety Stops. Mandatory
Safety Stops, for example due to continuous ascent rate violations, are still prompted.

65

If a deep stop is violated, it does not cause the dive computer to go into an error (Er)
mode. However, a penalty time is added to the subsequent decompression.

In the MIXED mode, the Deep stops are always activated.

NOTE

With Deep Stops ON, the Recommended Safety Stops will still
be activated at the end of the dive.

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6. DIVING

This section contains instructions on how to operate the dive computer and interpret
its displays. The dive computer is easy to use and read. Each display shows only the
data relevant to that specific diving mode.

6.1. Diving in the AIR mode (DIVE Air)

This section contains information on diving with standard air. To activate the DIVE Air
mode, please refer to Section 5.9.1. Accessing DIVE mode.

DIVE HAS JUST BEGUN AND
AVAILABLE NO-DECOMPRESSION
TIME IS OVER 99 MINUTES SO NO

VALUE IS DISPLAYED.

NOTE

The dive computer will remain in the SURFACE mode at depths
less than 1.2 m/4 ft. At depths greater than 1.2 m/4 ft the instru­ment will go into the DIVE mode automatically. However, it is re­commended that you activate the SURFACE mode manually
before entering the water in order to perform the necessary dive
pre-checks.

NOTE

The default fields shown on your dive computer in the DIVE mode
are the ones you select while in the SURFACE mode.

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6.1.1. Basic dive data

During a No-decompression dive, the following information is displayed:

•

your present depth in meters/feet

•

the available no-decompression time in minutes as NO DEC TIME

•

the ascent rate presented as a bar graph on the right side

•

the Diver Attention Symbol if surface interval should be prolonged (see Table 7.1,
Alarms)

DIVE DISPLAY - PRESENT DEPTH IS 15 M,
NO-DECOMPRESSION STOP TIME LIMIT 46 MIN.
MAXIMUM DEPTH DURING THIS DIVE WAS 21.5 M,

ELAPSED DIVE TIME 22 MIN.

Alternative displays, by pressing the UP/DOWN buttons, show:

•

the elapsed dive time in minutes, shown as DIVE TIME

•

the water temperature in °C/°F

•

the maximum depth during this dive in meters/feet, indicated as MAX

•

the current time, shown as TIME

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DOWN BUTTON TOGGLES
BETWEEN MAXIMUM DEPTH,
CURRENT TIME AND TANK

PRESSURE.

UP BUTTON TOGGLES
BETWEEN DIVE TIME AND
WATER TEMPERATURE.

In addition, with the optional wireless transmission enabled:

•

the Remaining Air-time in the left center window indicated as AIR TIME

•

the cylinder pressure in bar (or psi) displayed in the lower left corner

•

the cylinder pressure graphically displayed on the left side

6.1.2. Bookmark

It is possible to record bookmarks in the profile memory during a dive. These bookmarks
are displayed when scrolling the profile memory on the display. The bookmarks are
also shown as annotations in the downloadable Suunto DM4 with Movescount software.

The bookmark logs the depth, time, and water temperature, as well as compass
heading (if the compass has been enabled) and tank pressure when available.

69

To make a bookmark in the profile memory during a dive, press the SELECT button.
A brief confirmation will be given.

A BOOKMARK IS PLACED
IN THE PROFILE MEMORY
DURING A DIVE BY PRESSING

THE SELECT BUTTON.

6.1.3. Tank pressure data

When using the optional wireless pressure transmitter, the pressure of your scuba
cylinder in bars (or psi) is shown digitally in the lower left corner of the alternative dis­play. Whenever you start a dive, the remaining air time calculation begins. After 30–60
seconds (sometimes more, depending on your air consumption), the first estimation
of remaining air time is shown in the left center window of the display. The calculation
is always based on the actual pressure drop in your cylinder and automatically adapts
to your cylinder size and current air consumption.

CURRENT TANK PRESSURE

IS 165 BAR AND THE REMAINING

AIR TIME IS 52 MINUTES.

70

The change in your air consumption is based on constant one second interval pressure
measurements over 30–60 second periods. An increase in air consumption influences
the remaining air time rapidly, while a drop in air consumption increases the air time
slowly. In this way, an over optimistic air time estimation, caused by a temporary drop
in air consumption, is avoided.

The remaining air time calculation includes a 35 bar/500 psi safety reserve. This means
that when the instrument shows the air time to be zero, there is still about 35 bar/500
psi of pressure left in your cylinder, depending on your air consumption rate. With a
high consumption rate, the limit will be closer to 50 bar/700 psi and with a low rate
closer to 35 bar/500 psi.

NOTE

Filling your BC affects the air time calculation due to the temporary
increase in air consumption.

NOTE

The remaining air time is not displayed when either deep stops
or the decompression ceiling have been activated. You can recall
the remaining air time by long-pressing the DOWN button, but
the ceiling disappears.

NOTE

A change of temperature will affect the cylinder pressure and
consequently the air time calculation.

Low Air Pressure Warnings

The dive computer will warn you with three (3) audible double beeps and a blinking
pressure display when the cylinder pressure reaches 50 bar/700 psi.

71

Three (3) double beeps are also heard when the cylinder pressure goes down to the
user-selected alarm pressure, and when the remaining air time reaches zero.

6.1.4. Ascent rate indicator

The ascent rate is displayed graphically along the right hand side with a vertical bar.
When the maximum allowed ascent rate is exceeded, the lower segment of the bar
starts to blink with the top segment staying solid, indicating that the maximum ascent
rate has been exceeded.

NORMAL

ASCENT

RATE.

ACTIVATED BACKLIGHT, ALARM

AND A BLINKING ASCENT RATE BAR
GRAPH INDICATE YOU ARE ASCENDING
FASTER THAN 10 M/MIN. YOU ARE ADVISED

TO MAKE A MANDATORY SAFETY STOP

WHEN YOU REACH A DEPTH OF 6 M.

WARNING

DO NOT EXCEED THE MAXIMUM ASCENT RATE! Rapid as­cents increase the risk of injury. You should always make the
Mandatory and Recommended Safety Stops after you have ex­ceeded the maximum recommended ascent rate. If this Mandatory
Safety Stop is not completed, the decompression model will
penalize your next dive(s). Continuous ascent rate violations will
result in Mandatory Safety Stops. When Recommended Deep
Stop is enabled, the length is indicated in seconds.

72

6.1.5. Safety Stops and Deep Stops

If Deep Stops are not used, a three (3) minute Recommended Safety Stop is prompted
after every dive to over 10 m.

DURING DESCENT,
YOU'RE SHOWN THAT A
DEEPSTOP IS NEEDED AT

THE DEPTH OF 16 M.

DURING ASCENT, YOU'RE
ADVICED TO MAKE A DEEP
STOP AT 16 M FOR THE
DURATION SHOW BY THE

TIMER (42 S REMAINING).

6.1.6. Stopwatch (Timer)

You can also use a stopwatch during diving for various timing purposes. To activate
the stopwatch in the DIVE mode, long-press the MODE button, then start and stop it
by short-pressing the SELECT button.

73

6.1.7. Decompression dives

When your NO DEC TIME becomes zero, your dive changes into a decompression
dive. Therefore, you must perform one or more decompression stops on your way to
the surface. The NO DEC TIME on your display will be replaced by an ASC TIME,
and a CEILING notation will appear. An upward pointing arrow will also prompt you
to start your ascent.

If you exceed the no-decompression limits on a dive, the dive computer will provide
the decompression information required for ascent. After this, the instrument will
continue to provide subsequent interval and repetitive dive information.

Rather than requiring you to make stops at fixed depths, the dive computer lets you
decompress within a range of depths (continuous decompression).

The ascent time (ASC TIME) is the minimum amount of time needed to reach the
surface in a decompression dive. It includes:

•

the time needed at the deep stop

•

the time needed to ascend to the ceiling at an ascent rate of 10 m/33 ft per minute.
The ceiling is the shallowest depth to which you should ascend.

•

the time needed at the ceiling

•

the time needed at the Mandatory Safety Stop (if any)

•

the time needed to reach the surface after the ceiling and Safety Stops have been
completed

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WARNING

YOUR ACTUAL ASCENT TIME MAY BE LONGER THAN DIS­PLAYED BY THE INSTRUMENT! The ascent time will increase
if you:

•

remain at depth

•

ascend slower than 10 m/33 ft per minute or

•

make your decompression stop deeper than at the ceiling

These factors will also increase the amount of air required to
reach the surface.

Ceiling, ceiling zone, floor and decompression range

When in decompression, it is important that you understand the meaning of ceiling,
floor, and decompression range.

•

The ceiling is the shallowest depth to which you should ascend when in decom­pression. At this depth, or below, you must perform all stops.

•

The ceiling zone is the optimum decompression stop zone. It is the zone between
the minimum ceiling and 1.2 m/4 ft below the minimum ceiling.

•

The floor is the deepest depth at which the decompression stop time will not in­crease. Decompression will start when you pass this depth during your ascent.

•

The decompression range is the depth range between the ceiling and floor. Within
this range, decompression takes place. However, it is important to remember that
the decompression will be very slow at, or close to, the floor.

75

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 recom­mends 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 air 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.

76

Display below the floor

The blinking ASC TIME sign and an upward pointing arrow indicate that you are below
the floor. You should start your ascent immediately. The ceiling depth is shown on the
left side, and the minimum total ascent time on the right side of the center window.
Below is an example of a decompression dive without Deep Stops, below the floor.

UPWARD POINTING ARROW, BLINKING ASC

TIME AND AN ALARM TELL YOU TO ASCEND.

MINIMUM TOTAL ASCENT TIME INCLUDING SAFETY

STOP IS 9 MINUTES. CEILING IS AT 3 M.

Display above the floor

When you ascend above the floor, the ASC TIME sign stops blinking and the upward
pointing arrow disappears. Below is an example of a decompression dive above the
floor.

UPWARD POINTING ARROW HAS

DISAPPEARED AND ASC TIME LABEL HAS

STOPPED BLINKING, MEANING YOU ARE IN

THE DECOMPRESSION RANGE.

Decompression will now begin, but is very slow. Therefore, you should continue your
ascent.

77

Display at the ceiling zone

When you reach the ceiling zone, the display will show you two arrows pointing at
each other (the “hour glass” icon). Below is an example of a decompression dive at
the ceiling zone.

TWO ARROWS POINT AT EACH OTHER

“HOUR GLASS”. YOU ARE IN THE OPTIMUM CEILING

ZONE AT 3 M AND YOUR MINIMUM ASCENT TIME IS

9 MINUTES.

During the decompression stop, ASC TIME will count down towards zero. When the
ceiling moves upwards, you can ascend to the new ceiling. You may surface only after
the ASC TIME and CEILING labels have disappeared, which means that the decom­pression stop and any Mandatory Safety Stop have been completed. You are advised,
however, to stay until the STOP sign has also disappeared. This indicates that the
three (3) minute Recommended Safety Stop has also been completed.

Display above the ceiling

If you ascend above the ceiling during a decompression stop, a downward pointing
arrow will appear and a continuous beeping starts.

78

DECOMPRESSION DIVE, ABOVE CEILING.

NOTE DOWNWARD POINTING ARROW, ER WARNING

AND ALARM. YOU SHOULD IMMEDIATELY ( WITHIN

3 MINUTES) DESCEND TO OR BELOW CEILING.

In addition, an Error warning (Er) reminds you that you have only three (3) minutes to
correct the situation. You must immediately descend to, or below, the ceiling.

If you continue to violate the decompression, the dive computer will go into a permanent
Error Mode. In this mode, the instrument can only be used as a depth gauge and timer.
You must not dive again for at least 48 hours. (Refer to Section 5.6. Error conditions).

6.2. Diving in the MIXED mode

The MIXED mode is the first dive mode available in Suunto D9tx. The mode is used
when diving with air or with oxygen- or helium-enriched gas mixes.

6.2.1. Before diving in the MIXED mode

If set to theMIXED mode, the correct oxygen percentage of the gas in your cylinder
must always be entered into the computer to ensure correct nitrogen and oxygen
calculations. The dive computer adjusts its mathematical nitrogen and oxygen calcu­lation models accordingly. The dive computer will not accept fractional percentage
values of oxygen concentration. Do not round up fractional percentages. For example,

31.8% oxygen should be entered as 31%. Rounding up will cause inert gas percentages

79

to be understated and will affect decompression calculations. If you want to adjust the
computer to provide more conservative calculations, use the personal adjustment
feature to affect decompression calculations, or reduce the PO2setting to affect oxygen
exposure according to the entered O2% and PO2values. Calculations based on nitrox
use result in longer no-decompression times and shallower maximum depths than
diving with air.

As a safety precaution, the oxygen calculations in the computer are made with an
oxygen percentage of 1% + set O2% .

When the dive computer is set in mode, the Dive Planning mode calculates using the
O2% and PO2values that are currently in the computer.

To set the nitrox, trimix and/or heliox mixes, refer to Section 5.8.1. Setting the gases.

Default gas mix settings

In the MIXED mode, the Suunto D9tx allows you to set 1–8 gas mixes containing
8–99% oxygen and 0–92% helium.

In the MIXED mode, the default setting is standard air (21% O2and 0% He). It remains
in this setting until the O2% is adjusted to any other percentage of oxygen (8%–99%),
or the He% is adjusted to any other percentage of helium (0–92%). The default setting
for maximum oxygen partial pressure is 1.4 bar, however you are able to set it in the
range of 0.5–1.6 bar.

80

6.2.2. Oxygen and helium displays

When the MIXED mode is activated, the display will show the information in the figure
below. In the MIXED mode, the maximum operational depth is calculated based on
set O2%, He% and PO2values.

If set to the MIXED mode, the Suunto D9tx will additionally show on the alternative
display:

•

the oxygen percentage, labeled O2%

•

the helium percentage, labeled He%

•

the set oxygen partial pressure limit, labeled PO

2

•

the current oxygen toxicity exposure, labeled OLF%

•

maximum depth

•

current time

•

water temperature

•

dive time

•

tank pressure

81

DOWN BUTTON

TOGGLES BETWEEN

O

2

/HE, MAXIMUM
DEPTH, CURRENT
TIME, AND TANK

PRESSURE.

UP BUTTON

TOGGLES

BETWEEN PO

2

,

OLF, DIVE TIME

AND WATER

TEMPERATURE.

6.2.3. Oxygen limit fraction (OLF%)

If set to the MIXED mode, in addition to tracking the diver's exposure to inert gas, the
instrument tracks the exposure to oxygen. These calculations are treated as entirely
separate functions.

The dive computer calculates separately for Central Nervous System oxygen toxicity
(CNS) and Pulmonary Oxygen toxicity, the latter measured by the addition of Oxygen
Toxicity Units (OTU). Both fractions are scaled so that the maximum tolerated exposure
for each is expressed as 100%.

The Oxygen Limit Fraction (OLF%) displays only the value of the higher of the two
calculations. The oxygen toxicity calculations are based on the factors listed in Sec-
tion 10.3. Oxygen exposure .

82

6.2.4. Gas change and multiple breathing gas mixes

The Suunto D9tx allows gas changes to enabled gas mixes during the dive. When the
maximum operating depth allows for a gas change, the dive computer prompts you
to change the gas. When PO2permits better decompression gas to be used, the dive
computer prompts it automatically if it is set as primary. Gas changes are made by
following the procedure below:

NOTE

Mix number, O2%, He and PO2for the mixes are shown when
scrolling. If the set PO2limit is exceeded , it will be shown with
the PO2value blinking. The dive computer does not allow you to
change to a gas whose set PO2is exceeded. In such a case, the
mix is shown but cannot be selected. If the PO2is less than 0.18
bar, the dive computer gives an alarm.

83

NOTE

If no button is pressed in 15 seconds, the dive computer will go
back to the dive display without changing the gas mix. Upon as­cent, the computer prompts you to change gas when the PO

2

level you have set for the next mix allows a gas change. The
prompt is a low priority alarm followed by the "Change gas" beep,
sounded once. The Gas mix (O2%, He) value blinks.

6.3. Diving in the GAUGE mode (DIVE Gauge)

If set to the GAUGE mode, the dive computer can be used as a bottom timer or as a
free diving instrument.

In the GAUGE mode, the total dive time is always displayed in minutes in the lower
right corner. In addition, a Dive Timer in the center window displays time in minutes
and seconds. The center window Dive Timer is activated at the start of the dive and
it can be reset during the dive and used as a stopwatch by pressing the SELECT
button.

BY PRESSING THE SELECT

BUTTON DURING A DIVE, A BOOK­MARK IS WRITTEN IN THE PROFILE
MEMORY, THE DIVE TIMER IS RESET,

AND THE PREVIOUSLY-TIMED

INTERVAL IS DISPLAYED BELOW.

Tank pressure (if enabled) is also displayed during the dive.

NOTE

The GAUGE mode does not provide decompression information.

84

NOTE

There is no ascent rate monitoring in the GAUGE mode.

NOTE

If you dive with the GAUGE mode, it is not possible to change
between the modes before the no fly time has counted down.

85

7. AFTER DIVING

Once back at the surface, Suunto D9tx continues to provide post-dive safety information
and alarms. Calculations to enable repetitive dive planning also help to maximize diver
safety.

Table 7.1. Alarms

IndicationSymbol on display

Diver Attention Symbol - Extend Surface Interval

Violated Decompression Ceiling or Too Long Bottom
Time

Do Not Fly Symbol

7.1. Surface interval

An ascent to any depth shallower than 1.2 m/4 ft will cause the DIVE display to be
replaced by the SURFACE display:

IT IS 6 MINUTES SINCE YOU SURFACED FROM A 35-MINUTE DIVE.

THE MAXIMUM DEPTH WAS 21.5 M. THE PRESENT DEPTH IS 0.0 M. THE
AIRPLANE SYMBOL AND NO-FLY VALUE INDICATE THAT YOU SHOULD NOT FLY
FOR 14 HOURS, 28 MINUTES. THE DIVER ATTENTION SYMBOL INDICATES THAT

YOU SHOULD PROLONG YOUR SURFACE INTERVAL TIME.

86

Or, in the alternative displays, the following information will be shown:

•

maximum depth of last dive in meters/feet

•

dive time of last dive in minutes, shown as DIVE TIME

•

the current time, shown as TIME

•

the current temperature in °C/°F

•

cylinder pressure in bar/psi (if enabled)

If set to MIXED mode, the following information will also be shown:

•

the oxygen percentage labeled O2%

•

the oxygen partial pressure labeled PO

2

•

the current oxygen toxicity exposure labeled OLF%

7.2. Dive numbering

Several repetitive dives are considered to belong to the same repetitive dive series
when the dive computer has not counted the no-fly time to zero. Within each series,
the dives are given individual numbers. The first dive of the series will be numbered
as DIVE 1, the second as DIVE 2, the third as DIVE 3, and so on.

If you start a new dive with less than five (5) minutes of surface interval time, the dive
computer interprets this as a continuation of the previous dive and the dives are con­sidered to be the same. The diving display will return, the dive number will remain
unchanged, and the dive time will begin where it left off. After five (5) minutes on the
surface, subsequent dives are, by definition, repetitive. The dive counter displayed in
the Planning mode will increment to the next number if another dive is made.

87

7.3. Repetitive dive planning

The Suunto D9tx includes a dive planner that allows you to review the no-decompres­sion limits on a subsequent dive, taking the residual inert gas loading of previous dives
into consideration. The DIVE PLANNING mode is explained in Section 7.5. DIVE
PLANNING mode (PLAN NoDec).

7.4. Flying after diving

In the DIVE mode, the no-fly time is displayed in the center window next to the airplane
image. In the TIME mode, the airplane image is shown in the top left corner. Flying
or traveling to a higher altitude should be avoided at any time when the computer is
counting down the no-fly time.

The no-fly time is always at least 12 hours, or equivalent to the so-called desaturation
time (if longer than 12 hours). For desaturation times lower than 70 minutes, no no­fly time is given.

In the Permanent Error mode and FREE mode, the no-fly time is 48 hours.
The Divers Alert Network (DAN) recommends the following on no-fly times:

•

A minimum surface interval of 12 hours would be required in order to be reasonably
assured a diver will remain symptom free upon ascent to altitude in a commercial
jetliner (altitude up to 2,400 m/8,000 ft)

88

•

Divers who plan to make daily, multiple dives for several days, or make dives that
require decompression stops, should take special precautions and wait for an ex­tended interval beyond 12 hours before a flight. Further, the Undersea and Hyper­baric Medical Society (UHMS) suggests divers using standard air cylinders and
exhibiting no symptoms of decompression illness wait 24 hours after their last dive
to fly in an aircraft with cabin pressure up to 2,400 m/8,000 ft. The only two excep­tions to this recommendation are:

•

If a diver has less than 2 hours total accumulated dive time in the last 48 hours,
a 12 hour surface interval before flying is recommended

•

Following any dive that required a decompression stop, flying should be delayed
for at least 24 hours, and if possible, for 48 hours

•

Suunto recommends that flying is avoided until all the DAN and UHMS guidelines,
as well as the dive computer’s no-fly conditions, are satisfied

7.5. DIVE PLANNING mode (PLAN NoDec)

The DIVE PLANNING mode displays no-decompression times for a new dive, taking
into account the effects of previous dives.

When entering the DIVE PLANNING mode (PLAN NoDec) mode, the display first
briefly shows the remaining desaturation time before going into plan mode.

By pressing the UP/DOWN buttons, you can scroll the no-decompression limits in 3
m/10 ft increments ending at 45 m/150 ft. No-decompression limits longer than 99
minutes are displayed as “—“.If the O2% is too high for the planned depth, NA is dis­played instead of a numerical no-decompression limit.

89

WHEN ENTERING THE PLAN MODE
THE DISPLAY FIRST BRIEFLY SHOWS THE
REMAINING DESATURATION TIME BEFORE
GOING INTO PLAN MODE. USE UP AND
DOWN BUTTONS TO SCROLL DIFFERENT
NO-DECOMPRESSION LIMITS.
NO-DECOMPRESSION LIMITS LONGER

THAN 99 MINUTES ARE DISPLAYED AS “–”.

The Planning mode takes into account the following information from previous dives:

•

any calculated residual nitrogen

•

all dive history for the past four days

The no-decompression times given for different depths will therefore be shorter than
before your first “fresh” dive.

You can exit the DIVE PLANNING mode by pressing the MODE button.

NOTE

The DIVE PLANNING mode is disabled in GAUGE mode and in
Error mode (see Section 5.6. Error conditions).
The DIVE PLANNING mode calculates no-decompression times
for Mix1 only. If additional mixes are enabled in the MIXED mode,
they do not affect the calculations in (PLAN NoDec) mode.

90

Higher Altitude and conservative Personal Adjustment settings will shorten the no­decompression time limits. These limits at different Altitude and Personal Adjustment
setting selections are explained in Section 5.9.4. Diving at altitude and in Section 5.9.5.
Personal adjustments.

7.5.1. Dive numbering shown during dive planning

Dives belong to the same repetitive dive series if the instrument was still counting
down the no-fly time at the beginning of the dive.

The surface interval must be at least five (5) minutes for a dive to be considered a
repetitive dive. Otherwise, it is considered a continuation of the same dive. The dive
number will not change and the dive time will continue where it left off. (Refer also to
Section 7.2. Dive numbering ).

7.6. MEMORY mode

The memory options in the MEMORY mode include dive logbook (MEM Logbook)
and dive history (MEM History). They are accessed from the DIVE mode and you can
toggle between them by using the UP/DOWN buttons.

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The dive time and date are registered in the Logbook memory. Always check before
diving that the time and date are correctly set, especially after traveling between differ­ent time zones.

7.6.1. Dive logbook (MEM Logbook)

The Suunto D9tx has a very sophisticated, high capacity Logbook and Profile Memory.
The data is recorded in the profile memory based on the selected sample rate.

Dives shorter than the recording interval are not registered (refer to Section 5.8.7.
Setting the sample rate).

The END OF LOGS text is displayed between the oldest and most recent dive. The
following information will be shown on three pages:

THERE ARE THREE PAGES OF LOGBOOK DIVE INFORMATION. USE

SELECT BUTTON TO SCROLL BETWEEN LOGBOOK PAGES I, II, AND III.

THE DATA OF THE MOST RECENT DIVE IS SHOWN FIRST. YOU CAN

SCROLL THE GRAPHICAL DIVE PROFILE ON PAGE III WITH UP BUTTON.

Page I, main display

•

maximum depth

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NOTE

Depending on the sampling rate, the reading may differ from
the maximum depth reading of the Dive History up to 0.3 m/1
ft.

•

date of dive

•

type of dive (AIR, MIXED, GAUGE)

•

dive start time

•

dive number

•

oxygen percentage for the first used gas mix

•

total dive time (in minutes in all modes)

Page II

•

maximum depth

•

average depth

•

consumed pressure (if enabled)

•

warnings

Page III

•

depth/time profile of the dive

•

water temperature

•

tank pressure (if enabled)

NOTE

The memory will retain approximately the last 36 hours of dive
time. After that, when new dives are added, the oldest dives are
deleted. The contents of the memory will remain when the battery
is changed (providing that the battery has been replaced according
to the instructions).

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NOTE

Several repetitive dives are considered to belong to the same
repetitive dive series if the no-fly time has not ended. See Sec­tion 7.2. Dive numbering for further information.

7.6.2. Dive history

The dive history is a summary of all the dives recorded by the dive computer.
The following information will be shown on the display:

DIVE HISTORY DISPLAY.

TOTAL NUMBER OF DIVES, DIVE

HOURS AND MAXIMUM DEPTH.

The Dive History Memory can hold a maximum of 999 dives and 999 diving hours.
When these maximum values are reached, the counters will start again from zero.

NOTE

The maximum depth can be reset to 0.0 m/0 ft using the PC Inter­face unit and the downloadable Suunto DM4 software.

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7.7. Suunto DM4 with Movescount

The Suunto DM4 with Movescount (DM4) is an optional software that greatly enhances
the functionality of your Suunto D9tx. With the DM4 software, you can download dive
data from your dive computer to your laptop. After that, you can view and organize all
the data recorded with your Suunto D9tx. You can plan dives (with Suunto Dive
Planner), print copies of your dive profiles, and also upload your dive logs to share
with your friends at http://www.movescount.com (see Section 7.8. Movescount). You
can always download the latest version of the DM4 from http://www.suunto.com.
Please check for updates regularly as new features are constantly being developed.
The following data is transferred from your dive computer to your laptop (optional,
cable required):

• depth profile of the dive

• dive time

• preceding surface interval time

• dive number

• dive start time (year, month, day, and time)

• dive computer settings

• oxygen percentage settings and maximum OLF (in the MIXED mode)

• tissue calculation data

• real-time water temperature

• tank pressure data (if enabled)

• additional dive information (for example, SLOW and Mandatory Safety Stop viola­tions, Diver Attention Symbol, Bookmark, Surfaced Mark, Decompression Stop
Mark, and Ceiling Error Mark)

• dive computer serial number

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• personal information (30 characters)
By using the DM4, you are able to enter setup options such as:

•

input a personal, 30-character field into the Suunto D9tx

•

reset the Scuba History's maximum depth to zero

•

reset all Free Dive History

•

manually add comments, multimedia and other personal information to the PC­based dive data files

7.8. Movescount

Movescount is an online sports community that offers you a rich set of tools to manage
all you sports and create engaging stories about your diving experiences. Movescount
offers you new ways to get inspired and share your best dives with other community
members!

To connect to Movescount:

1.

Go to www.movescount.com.

2.

Register and create your free Movescount account.

3.

Download and install the Suunto DM4 with Movescount software from the
Movescount.com website if you do not already have the DM4 installed on your
laptop

To transfer data:

1.

Connect your dive computer to your laptop.

2.

Download your dives to the DM4 on your laptop.

3.

Follow the instructions on the DM4 on how to transfer your dives to your
Movescount.com account.

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8. CARE AND MAINTENANCE OF MY SUUNTO DIVING COM-

PUTER

The SUUNTO dive computer is a sophisticated precision instrument. Although it is
designed to withstand the rigors of scuba diving, you must treat it with the same
proper care and caution as any other precision instrument.

•

WATER CONTACTS AND PUSH BUTTONS
Contamination or dirt on the water contacts/connector or push buttons may prevent

the automatic activation of the Dive Mode and cause problems during the data
transfer. Therefore, it is important that the water contacts and push buttons are
kept clean. If the water contacts are active (AC text remains on display) or the Dive
Mode activates on its own, the reason for this is probably contamination or invisible
marine growth, which may create an electric current between the contacts. It is
important that the dive computer is carefully washed in fresh water after the day’s
diving is completed. The contacts can be cleaned with fresh water and, if necessary,
a mild detergent and a soft brush. Sometimes it might be necessary to remove the
instrument from the protective boot for cleaning.

•

CARE OF YOUR DIVE COMPUTER

NEVER try to open the case of the dive computer.•

• Have your dive computer serviced every two years or after 200 dives (whichever

comes first) by an authorized dealer or distributor. This service will include a
general operational check, replacement of the battery, and water resistance
check. The service requires special tools and training. Therefore, it is advisable
to contact an authorized SUUNTO dealer or distributor for service. Do not at­tempt to do any servicing that you are not sure of.

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• Should moisture appear inside the case or battery compartment, immediately
have the instrument checked by your SUUNTO dealer or distributor.

• The specific scratch guard for D4i, D6i, and D9tx is designed to help the display
from getting scratched. One scratch guard is included in the product package
and they can also be purchased separately from your nearest retailer. The
scratch guard is easy to attach and also to replace if needed (for more inform­ation, see the instructions on www.suunto.com).

• Should you detect scratches, cracks or other such flaws on the display that
may impair its durability, immediately have it replaced by your SUUNTO dealer
or distributor.

• Wash and rinse the unit in fresh water after every use.

• Protect the unit from shock, extreme heat, direct sunlight, and chemical attack.
The dive computer cannot withstand the impact of heavy objects like scuba
cylinders, nor chemicals like gasoline, cleaning solvents, aerosol sprays, adhes­ive agents, paint, acetone, alcohol, and so on. Chemical reactions with such
agents will damage the seals, case and finish.

• Store your dive computer in a dry place when you are not using it.

• The dive computer will display a battery symbol as a warning when the power
gets too low. When this happens, the instrument should not be used until the
battery has been replaced.

• Do not fasten the strap of your dive computer too tightly. You should be able
to insert your finger between the strap and your wrist. Shorten the strap by
cutting it if you do not expect to need the extra length.

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•

MAINTENANCE
The instrument should be soaked, thoroughly rinsed with fresh water, then dried

with a soft towel after each dive. Make sure that all salt crystals and sand particles
have been flushed out. Check the display and the transparent battery compartment
cover for possible moisture or water. DO NOT use the dive computer if you detect
any moisture or water inside. In order to limit corrosion damage, remove the battery
and moisture from the battery compartment. Contact an authorized Suunto dealer
for battery replacement or other service.

CAUTION!

• Do not use compressed air to blow water off the unit.

• Do not use solvents or other cleaning fluids that might cause damage.

• Do not test or use the dive computer in pressurized air.

•

WATER RESISTANCE INSPECTION
The water resistance of the unit must be checked after replacing the battery or

after other service operations. The check requires special equipment and training.
You must frequently check the transparent battery compartment cover and the
display for any sign of leaks. If you find moisture inside your dive computer, there
is a leak. A leak must be corrected without delay as moisture will seriously damage
the unit, even beyond repair. SUUNTO does not take any responsibility for damage
caused by moisture in the dive computer unless the instructions of this manual are
carefully followed. In the event of a leak, immediately take the dive computer to
an authorized SUUNTO dealer or distributor.

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FAQs
WHAT CAN I DO TO MY SUUNTO DIVING COMPUTER MYSELF?

NOTE

It is advisable to contact an authorized Suunto service, distributor
or retailer for any repairs. Batteries and straps can be replaced
by the user when the change is made in a proper manner to avoid
any leakage of water into the battery compartment or computer.
Original battery replacement and strap kits must be used.

Contact the Suunto retailer for battery change.
Instructions for changing batteries and straps can be found in the user manuals or at

www.suunto.com and the user videos at www.suunto.tv.

WHAT ARE ORIGINAL SUUNTO ACCESSORIES?

Original Suunto accessories are only distributed through Suunto's worldwide network
of authorized Suunto distributors and retailers.

Original Suunto accessories are tested to be compatible with Suunto products and
can be used safely.

NOTE

Damage caused by non-original accessories will not be covered
by warranty.

HOW TO GET MORE INFORMATION

You can find service & warranty information in these pages by searching the FAQs.
If you do not find the answer in the FAQs, you can also send a support request. To

be able to send a support request you have to register in the system. REGISTER
NOW.

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You can also contact our European help desk by telephone at [phone]. The
cost of the call is that of a normal call to Finland. The call center is open Mon-Fri,
24h/day. The service is provided in English all the time. Other languages—French,
German, Swedish, Japanese, Spanish and Finnish—are only provided during local
business hours. Call center professionals can answer customer questions regarding
diving products, outdoor products and compasses.

HOW DO I KNOW IF MY SUUNTO PRODUCT IS COVERED BY WARRANTY?

You can check the proof of purchase, which has to be two (2) years or less. You can
also check the serial number of your unit.

Does repairing my Suunto product extend the warranty?
As far as the national laws permit, repairing the product does not extend or otherwise

affect the warranty period. However, part(s) repaired or replacement product(s) provided
during the warranty period will be warranted for the remainder of the original warranty
period or for three (3) months from the date of repair or replacement, whichever is
longer.

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