Suunto COBRA User manual

SUUNTO
COBRA
EN
USER’S GUIDE

Arrows: - Decompression Stop at the Ceiling Depth - Mandatory Safety Stop Zone - Ascent Recommended - Must Descend
Quick Reference Guide
bar psi
°
F
°C
ft
MAXAVGPO2
NO DEC TIME
STOP
AIR TIME
TIME
SURF
DIVE
O2% ASC TIME
CEILING
OK
QUIT
SELECT
OPTIONS
NO
S
L
O
W
T
C
B
OLF
DIVE
m
°C
bar
Low Battery Warning
Cylinder Pressure Temperature Week Day Mode Text Personal Adjustment Mode Do Not Fly Icon Bar Graph: - Mode Indicator - Consumed Bottom Time - Oxygen Limit Fraction
Bar Graph: - Ascent Rate Indicator - Battery Power Indicator - Logbook Page Indicator
Present Depth Dive Counter
Plan Button
Scroll Button (increase value, ascend)
Remaining Air Time / Oxygen Percentage in Nitrox Mode
Current Time Display Surface Interval Time No Flying Time No-Decompression Time Total Ascent Time Safety Stop Time Dive Time Time Month,Day The Smart Button: - Activation - Backlight - Mode Operations
Maximum Depth Ceiling Depth on Decompression Stop Mandatory Safety Stop Depth Average Depth in Logbook Oxygen Partial Pressure AM/PM Indicator
Altitude Adjustment Mode Bookmark Symbol
Daily/DiveTime/Depth Alarm On Indicator
Diver Attention Symbol
Smart Button Indicators
Scroll Button Indicators Time (alternative display) Button
Scroll Button (decrease value, descend)
Fast Ascent Warning (SLOW) Safety Stop Warning Safety Stop Indicator

1
DEFINITION OF WARNINGS, CAUTIONS AND NOTES
Throughout this manual, special references are made when deemed important. Three
classifications are used to separate these references by their order of importance.
WARNING is used in connection with a procedure or situation that
may result in serious injury or death.
CAUTION is used in connection with a procedure or situation that
will result in damage to the product.
NOTE is used to emphasize important information.
COPYRIGHT, TRADEMARK AND PATENT NOTICE
This instruction manual is copyrighted and all rights are reserved. It may not, in whole
or in part, be copied, photocopied, reproduced, translated, or reduced to any media
without prior written consent from SUUNTO.
SUUNTO, COBRA, Consumed Bottom Time (CBT), Oxygen Limit Fraction (OLF),
SUUNTO Reduced Gradient Bubble Model (RGBM), Continuous Decompression
and their logos are all registered or unregistered trademarks of SUUNTO. All rights
are reserved.
Patents have been issued or applied for one or several features of this product.
CE
The CE mark is used to mark conformity with the European Union EMC
directive 89/336/EEC. The SUUNTO dive instruments fulfill all the required EU
directives.
FIOH, Laajaniityntie 1, FIN-01620 Vantaa, Finland, notified body no.0430, has
EC type-examined this type of personal protective equipment.
EN 250 Respiratory equipment - Open circuit self-contained compressed air diving
apparatus - Requirements, testing, marking.
The tank pressure gauge and the parts of this product used in measuring the tank
pressure meet the requirements set in the section of the European Standard EN 250
that concern tank pressure measurements. The instruments must be serviced by an
authorized dealer every second year or after 200 dives (whichever comes first).
PrEN 13319
PrEN 13319 “Diving accessories - Depth gauges and combined depth and time
measuring devices - Functional and safety requirements, test methods” is a
European diving depth gauge standard draft. The COBRA is designed to comply
with this draft standard.
ISO 9001
SUUNTO Oyj’s Quality Assurance System is certified by Det Norske Veritas to be
according to the ISO 9001 in all SUUNTO Oyj’s operations (Quality Certificate No.
96-HEL-AQ-220).

2
WARNINGS
SUUNTO Oyj does not assume any responsibility for losses or claims by third
parties, which may arise through the use of this device.
Due to continuous product development, the COBRA is subject to change without
notice.
WARNING!
READ THIS MANUAL! Carefully read this instruction manual in its entirety
paying close attention to all warnings listed below, including section 1.1. “Safety
Precautions”. Make sure that you fully understand the use, displays and limitations
of the dive computer because any confusion resulting from neglecting to follow
this instruction manual or from improper use of this device may cause a diver to
commit errors that may lead to serious injury or death.
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 exposures that tend to increase the risk of
decompression illness (DCI). Therefore, Suunto strongly recommends that the
device be not used for commercial or professional diving activity.
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 diver 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 WILL 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 measure of safety, you should consult a
physician regarding your fitness before diving.

3
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
PO2 OF 1.4 BAR SETTINGS!
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! Make sure 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 PRECHECKS! 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 and personal adjustments are correct. Also, exit the Data Transfer mode
before diving, as the computer does not automatically revert to Dive mode from
Data Transfer mode.
WARNING!
YOU ARE ADVISED TO AVOID FLYING ANY TIME THE COMPUTER
COUNTS DOWN THE NO-FLYING TIME. ALWAYS ACTIVATE THE
COMPUTER TO CHECK THE REMAINING NO-FLY TIME PRIOR TO
FLYING! The computer goes into the stand-by display automatically 5 minutes
after the dive has ended. The stand-by display shuts off after two hours. Flying
or traveling to a higher altitude within no-fly time can greatly increase the risk
of DCI. Review the recommendations given by Diver’s Alert Network (DAN) in
chapter 3.6.3. “Flying After Diving”. There can never be a flying after diving rule
that is guaranteed to completely prevent decompression illness!

4
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, it 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.
WARNING!
DO NOT EXPOSE THE COBRA DIVE COMPUTER WITH IT´S STANDARD
HOSE 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 INTOYOUR 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 there is a desire 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.
WARNING!
SET THE CORRECT ALTITUDE ADJUSTMENT MODE! WHEN DIVING at
altitudes greater than 300 m [1000 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 3000
m [10000 ft]. FAILURE TO SELECT the correct Altitude Adjustment setting or
diving above the maximum altitude limit will result in erroneous dive and planning
data.

5
WARNING!
SET THE CORRECT PERSONAL ADJUSTMENT 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.
NOTE!
It is not possible to change between Air, Nitrox and Gauge modes before the
instrument has counted down the no-flying time.
There is one exception to this: You can change from Air to Nitrox mode even
during the no-flying time. When planning both air and nitrox dives during the
same dive series, you should set the instrument in Nitrox mode and modify the
gas mix accordingly.
In Gauge mode, the no-flying time is always 48 hours.

6
TABLE OF CONTENTS
WARNINGS .................................................................................... 1
1. INTRODUCTION ....................................................................... 8
1.1. SAFETY PRECAUTIONS.........................................................................9
1.1.1. Emergency Ascents....................................................................9
1.1.2. Dive Computer Limitations .......................................................9
1.1.3. Nitrox .......................................................................................10
2. GETTING ACQUAINTED........................................................ 11
2.1. FUNCTIONS............................................................................................11
2.2. CONNECTING THE COBRA TO A REGULATOR ..............................11
2.3. PUSH BUTTONS ....................................................................................12
2.4. WATER CONTACTS ...............................................................................13
3. DIVING WITH THE COBRA................................................... 14
3.1. BEFORE DIVING....................................................................................14
3.1.1. Activation and Prechecks.........................................................14
3.1.2. Battery Power Indicator and Low Battery Warning.................15
3.1.3. Dive Planning [PLAN] ............................................................16
3.1.4. User Definable Functions and Alarms .....................................17
3.2. SAFETY STOPS ......................................................................................18
3.2.1. Recommended Safety Stop......................................................18
3.2.2. Mandatory Safety Stop ............................................................18
3.3. DIVING IN AIR MODE ..........................................................................20
3.3.1. Basic Dive Data .......................................................................20
3.3.2. Bookmark.................................................................................21
3.3.3. Cylinder Pressure Data ............................................................21
3.3.4. Consumed Bottom Time (CBT)...............................................23
3.3.5. Ascent Rate Indicator...............................................................23
3.3.6. Decompression dives ...............................................................24
3.4. DIVING IN NITROX MODE..................................................................28
3.4.1. Before Diving...........................................................................28
3.4.2. Oxygen Displays......................................................................29
3.4.3. Oxygen Limit Fraction (OLF) .................................................30
3.5. DIVING IN GAUGE MODE...................................................................31
3.6. AT THE SURFACE ..................................................................................32
3.6.1. Surface Interval........................................................................32
3.6.2. Dive Numbering.......................................................................33
3.6.3. Flying After Diving..................................................................34
3.7. AUDIBLE AND VISUAL ALARMS................................................35
3.8. HIGH ALTITUDE DIVES AND PERSONAL ADJUSTMENT ......37
3.8.1. Altitude Adjustment .................................................................37
3.8.2. Personal Adjustment ................................................................38
3.9. ERROR CONDITIONS ...........................................................................39

7
4. MENU BASED MODES........................................................... 40
4.1. MEMORIES AND DATA TRANSFER [1 MEMORY]...........................42
4.1.1. Logbook and Dive Profile Memory [1 LOGBOOK]...............42
4.1.2. Dive History Memory [2 HISTORY].......................................45
4.1.3. Data Transfer and PC-Interface [3 TR-PC]..............................45
4.2. SIMULATION MODE [2 SIMUL]..........................................................47
4.2.1. Dive Simulator [1 SIMDIVE]..................................................47
4.2.2. Dive Planning Simulator [2 SIMPLAN]..................................48
4.3. SET MODES [3 SET] ..............................................................................49
4.3.1. Dive Parameter Settings [1 SET DIVE] ..................................49
4.3.1.1. Altitude Adjustment and Personal Adjustment Settings
[1 AdJ MODE]........................................................................49
4.3.1.2. Dive Time Alarm Setting [2 d ALARM]....................50
4.3.1.3. Maximum Depth Alarm Setting [3 MAX DPTH] .....50
4.3.1.4. Nitrox/Oxygen Settings [4 NITROX] ........................50
4.3.2. Setting Time [2 SET TIME].....................................................51
4.3.2.1. Adjusting Time [1 AdJ TIME]....................................51
4.3.2.2. Adjusting Date [2 AdJ DATE]....................................51
4.3.2.3. Adjusting Daily Alarm [3 T ALARM] .......................51
4.3.3. Setting Preferences [3 SET PREF] ..........................................52
4.3.3.1. Backlight Setting [1 LIGHT] .....................................52
4.3.3.2. Dive Computer Units Setting [2 UNITS]...................52
4.3.3.3. Dive Computer Model Setting [3 MODEL] -
AIR/NITROX/GAUGE ..............................................52
5. CARE AND MAINTENANCE ................................................. 53
5.1. IMPORTANT INFORMATION ...............................................................53
5.2. CARE OF YOUR DIVE COMPUTER.....................................................54
5.3. MAINTENANCE .....................................................................................55
5.4. WATER RESISTANCE INSPECTION....................................................55
5.5. BATTERY REPLACEMENT ...................................................................55
5.6. DISPLAY SHIELD REPLACEMENT.....................................................59
5.7. COMPASS ATTACHMENT.....................................................................59
6. TECHNICAL DESCRIPTION .................................................. 60
6.1. OPERATING PRINCIPLES.....................................................................60
6.2. REDUCED GRADIENT BUBBLE MODEL, SUUNTO RGBM ...........62
6.3. OXYGEN EXPOSURE............................................................................63
6.4. TECHNICAL SPECIFICATION..............................................................64
7. WARRANTY ............................................................................. 67
8. GLOSSARY ............................................................................... 68

8
1. INTRODUCTION
Congratulations on your purchase of the SUUNTO COBRA advanced dive
computer. The Cobra builds on the Suunto tradition of delivering feature-rich
dive computers. The Cobra provides many new and enhanced features that cannot
be found in any other air-integrated dive computer. Push button controls access
a wide selection of choices. The display is optimized for the dive mode chosen.
This air-integrated dive computer is a compact and sophisticated multipurpose dive
instrument, designed to give you years of trouble-free service.
CHOICE OF OPERATING MODES AND SET-UP OPTIONS
User options for the Cobra are selected using the push buttons. Pre Dive
configuration and setup options include:
• Choice of operating mode - Air / Nitrox / Gauge
• Choice of unit - Metric / Imperial
• Maximum depth alarm
• Dive time alarm
• Backlight settings
• Clock, calendar, daily alarm
• Mix Oxygen fraction % (Nitrox mode only)
• Maximum PO2(Nitrox mode only)
• Altitude adjustment
• Personal adjustment
CONTINUOUS DECOMPRESSION WITH SUUNTO RGBM
The Suunto Reduced Gradient Bubble Model (RGBM) utilized in the Cobra predicts
both dissolved and free gas in 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.
In order to optimize how to respond to different added risk situations an additional
category of stop, referred to as a Mandatory Safety Stop, has been introduced. Also
a countdown for the Recommended Safety Stop is included. The combination of
stop types will depend on the specific dive situation.
To get the most from the safety benefits be sure to read the summary of the Suunto
Reduced Gradient Bubble Model on page 62.