SUUNTO MOSQUITO User Manual

EN

SUUNTO

MOSQUITO

USER’S GUIDE

Present Depth
Maximum Depth
Average Depth in Logbook
Fast Ascent Warning
(SLOW)
AC Indicator

Do Not Fly Icon

Arrows:

- Decompression Stop
at the Ceiling Depth

- Mandatory Safety Stop Zone

- Ascent Recommended

- Must Descend

Bar Graph:

- Ascent Rate

- Battery Power

- Mode Indicator

Diver Attention Symbol

Temperature
Maximum Depth
Mode Text
Oxygen Percentage in Nitrox
Mode
Week Day
Timer Hours and Minutes

Low Battery Warning

Current Time Display
No-Decompression Time
Surface Interval Time
No Flying Time
Total Ascent Time
Ceiling Depth on Decompression Stop
Safety Stop Time
Mandatory Safety Stop Depth and Time

Bar Graph:

- Mode Indicator

- Oxygen Limit Fraction

Altitude Adjustment
Mode

Personal Adjustment
Mode

AM/PM Indicator

Safety Stop Warning
Safety Stop Indicator

Dive Time

A

S

C

F

L

O

Dive Counter
Oxygen Partial Pressure
in Nitrox Mode
Time
Dual Time
Day, Month
Timer Seconds
Oxygen Partial Pressure

Daily Alarm
On Indicator

Dive Alarm
On Indicator

SUUNTO MOSQUITO

QUICK REFERENCE QUIDE

DEFINITION OF WARNINGS, CAUTIONS AND NOTES

Throughout this manual, special references are made when deemed important.
Three classifi cations are used to separate these references by their order of
im por tance.

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, MOSQUITO, Consumed Bottom Time (CBT), Oxygen Limit Frac tion
(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 di rec tive
89/336/EEC. The SUUNTO dive instruments fulfi ll all the required EU di rec tives.

1

FIOH, Laajaniityntie 1, FIN-01620 Vantaa, Finland, notifi ed body no.0430, has
EC type-examined this type of personal protective equipment.

This instrument must be serviced by an authorized dealer every second year or
after 200 dives (whichever comes fi rst). See chapter 6.

PrEN 13319

PrEN 13319 ”Diving accessories – Depth gauges and combined depth and time
measuring devices – Functional and safety requirements, test methods” is a
Eu ro pe an diving depth gauge standard draft. The MOSQUITO is designed to
comply with this draft standard.

ISO 9001

SUUNTO Oy’s Quality Assurance System is certifi ed by Det Norske Veritas to
be according to the ISO 9001 in all SUUNTO Oy’s operations (Quality Cer tifi cate
No. 96-HEL-AQ-220).

SUUNTO Oy 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 MOSQUITO is subject to change
without notice.

2

WARNING

Read this manual. Carefully read this instruction manual in its entirety
paying close attention to all warnings listed below, including chapter 1.1.
”Safety Pre cau tions”. 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 com mer cial 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.
Insuffi cient or improper training may cause diver to commit errors that may
lead to serious injury or death.

3

WARNING

There is always a risk of decompression illness (DCI) for any dive profi le even
if you follow the dive plan prescribed by dive tables or a dive computer. No
pro ce dure, 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 fi tness before diving.

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
as cend 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
in clud ing a depth gauge, submersible pressure gauge, timer or watch, and have
access to decompression tables whenever diving with a dive computer.

4

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
dis played, 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 not to fl y any time the computer counts down the no-fl ying
time. Always activate the computer to check the remaining no-fl y time
prior to fl ying. The computer goes into the stand-by display automatically 5
minutes after sur fac ing. Flying or traveling to a higher altitude within no-fl y
time can greatly increase the risk of DCI. Review the recommendations given
by Diver’s Alert Network (DAN) in chapter 3.2.3.4. “Flying After Diving”.
There can never be a fl ying 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 profi les 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.

5

WARNING

Do not dive with a cylinder of enriched air if you have not personally verifi ed
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 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 PO2 setting 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.

6

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.

WARNING

Freediving after scuba diving is not recommended. It is recommended to avoid
freediving for at least two hours and not to exceed fi ve meters [16 ft] after scuba
diving depending on your diving activity.

Suunto also recommends you to be trained in freediving technique and
physiology before conducting breath holding dives. No dive computer can
replace the need for proper dive training. Insuffi cient or improper training may
cause diver to commit errors that may lead to serious injury or death.

NOTE:

Changing from AIR to EAN mode is possible at any time. Changing from EAN
to AIR mode however requires you to wait until the no-fl ying time has counted
down. FREE mode is accessible at any time.

FREE mode is limited to 5 minutes, after which a warning is given. After 5+1
minutes the computer goes into error mode.

7

TABLE OF CONTENTS

1. INTRODUCTION ........................................................................................12

1.1. SAFETY PRECAUTIONS .................................................................... 13

1.1.1. Emergency Ascents ...................................................................... 14

1.1.2. Dive Computer Limitations ......................................................... 15

1.1.3. Nitrox ..........................................................................................15

1.1.4. Freediving .................................................................................... 15

2. GETTING ACQUAINTED ........................................................................... 17

2.1. FUNCTIONS ......................................................................................... 17

2.2. PUSH BUTTONS .................................................................................. 17

2.3. WATER CONTACTS.............................................................................19

2.4. TIME MODE [TIME]............................................................................20

2.4.1. Timekeeping Display ...................................................................20

2.4.2. Stopwatch [Timer] ....................................................................... 21

3. DIVING WITH THE MOSQUITO............................................................... 23

3.1 BEFORE DIVING .................................................................................. 24

3.1.1. Activation and Pre-checks .......................................................... 24

3.1.2. Battery Power Indicator and Low Battery Warning ..................... 26

3.1.3. User Defi nable Functions and Alarms ......................................... 28

3.1.3.1. Presetting Time Alarm ....................................................29

3.1.3.2. Presetting Dive Alarms ...................................................29

3.1.4. Bookmark Function ..................................................................... 29

3.2. SCUBA DIVING ................................................................................... 30

8

3.2.1. Diving with Air ............................................................................ 30

3.2.1.1. Dive Planning [PLAN] ................................................... 30

3.2.1.2. Presetting the Displays in the Air mode ..........................32

3.2.1.3. Basic Dive Data .............................................................. 32

3.2.1.4. Safety stops .................................................................... 34

3.2.1.4.1. Recommended Safety Stop .................................. 35

3.2.1.4.2. Mandatory Safety Stop ........................................ 35

3.2.1.5. Ascent Rate Indicator ...................................................... 37

3.2.1.6. Decompression dives ...................................................... 39

3.2.2. Diving with EAN (Nitrox) ........................................................... 45

3.2.2.1. Before Diving ................................................................45

3.2.2.2. Presetting the Displays in the EAN mode ......................46

3.2.2.3. Oxygen Displays ............................................................. 47

3.2.2.4. Oxygen Limit Fraction (OLF) ........................................ 48

3.2.3. At the Surface .............................................................................. 49

3.2.3.1. Surface Interval after an Air/EAN Dive ......................... 49

3.2.3.2. Diver Attention Symbol ..................................................51

3.2.3.3. Dive Numbering .............................................................51

3.2.3.4. Flying After Diving ......................................................... 52

3.2.4. High Altitude Dives and Personal Adjustment ............................ 53

3.2.4.1. Altitude Adjustment ........................................................ 53

3.2.4.2. Personal Adjustment ....................................................... 55

3.2.5. Error Conditions .........................................................................57

3.3. FREEDIVING .......................................................................................58

9

3.3.1. Before Diving in the Free mode ..................................................58

3.3.2. Presetting the Displays in the Free mode ..................................... 58

3.3.3. During the Freedive ..................................................................... 59

3.3.4. Freediving Day History................................................................59

3.3.5. Exceeding the Freediving Time Limit .........................................60

3.3.6. Surface Interval After a Freedive ................................................. 61

3.4. AUDIBLE AND VISUAL ALARMS .................................................... 62

4. SETTING MODE [SET] ..............................................................................65

4.1. SETTING TIME, DATE AND DUAL TIME [TIME ] .......................... 65

4.2. DAILY ALARM SETTING [ALM] ......................................................67

4.3. DIVE MODE SETTINGS [DIVE] ........................................................ 69

4.3.1. Set Air Mode ................................................................................ 69

4.3.2. Set EAN Mode ............................................................................. 71

4.3.3. Set Free Mode .............................................................................. 72

4.4. DIVE ALARM SETTINGS [DIVE AL] ............................................ 73

4.5. ALTITUDE, PERSONAL AND UNIT ADJUSTMENT SETTINGS ..

[AdJ] ..................................................................................................... 75

5. MEMORIES AND DATA TRANSFER [MEM] .......................................... 77

5.1. LOGBOOK AND DIVE PROFILE MEMORY [LOG] ........................ 78

5.2. DIVE HISTORY MEMORY [HIS]........................................................ 83

5.3. DATA TRANSFER AND PC-INTERFACE [TR-PC] ........................... 84

6. CARE AND MAINTENANCE .................................................................... 87

6.1. CARE OF YOUR MOSQUITO ............................................................. 87

6.2. MAINTENANCE .................................................................................. 88

10

6.3. WATER RESISTANCE INSPECTION ................................................. 89

6.4. BATTERY REPLACEMENT ................................................................ 90

7. TECHNICAL DESCRIPTION ..................................................................... 93

7.1. OPERATING PRINCIPLES ..................................................................93

7.2. REDUCED GRADIENT BUBBLE MODEL, SUUNTO RGBM ........ 96

7.3. OXYGEN EXPOSURE ......................................................................... 98

7.4. TECHNICAL SPECIFICATION ......................................................... 100

8. WARRANTY ..............................................................................................105

9. GLOSSARY ................................................................................................ 107

11

1. INTRODUCTION

Congratulations on your purchase of the SUUNTO MOSQUITO advanced wristop
dive computer. The Mosquito builds on the Suunto tradition of delivering feature­rich dive computers, providing different operating modes for different types of
diving. Push button controls access a wide selection of choices. The display is
optimized for the dive mode chosen and it incorporates a patented user defi nable
display fi eld. This dive computer is a compact and sophisticated multipurpose dive
instrument, designed to give you years of trouble-free usage.

CHOICE OF DIVING AND WATCH MODES

User options for the Mosquito are selected using the push buttons.

Pre dive confi guration and setup options include:

• Choice of operating mode – Air / Nitrox / Freediving

• Maximum depth alarm

• Dive time alarm

• Oxygen fraction % (Nitrox mode only)

• Oxygen partial pressure alarm limit (Nitrox mode only)

• Altitude adjustment

• Personal adjustment

• Choice of unit – Metric / Imperial

• Clock, calendar, daily alarm, stopwatch, dual time

• User defi nable display fi elds

12

CONTINUOUS DECOMPRESSION WITH SUUNTO RGBM

The Suunto Reduced Gradient Bubble Model (RGBM) utilized in the Mosquito
predicts both dissolved and free gas in blood and tissues of divers. It is a signifi cant
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 profi les.

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 specifi c dive situation.

To get the most from the safety benefi ts be sure to read the summary of the Suunto
Reduced Gradient Bubble Model in chapter 7.2.

1.1. SAFETY PRECAUTIONS

Do not attempt to use Mosquito without reading this instruction manual 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, the dive computer is an outstanding tool for assisting properly
trained, certifi ed divers in planning and executing sport dives. It is not a substitute for
certifi ed scuba instruction, including training in the principles of decompression.

13

Diving with enriched air mixtures (nitrox) exposes the user to risks 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 fi rst
receiving certifi ed training in this specialty.

1.1.1. EMERGENCY ASCENTS

In the unlikely event that Mosquito malfunctions during a dive, follow the
emergency procedures provided by your certifi ed dive training agency or,
alternatively,

STEP 1: Assess the situation calmly and then move promptly to less than 18 m

STEP 2: At 18 m [60 ft], slow down your ascent rate to 10 m/min [33 ft/min]

STEP 3: Stay there as long as you assess your air supply will safely allow. After

[60 ft].

and move to a depth between 3 and 6 meters [10 to 20 ft].

reaching the surface stay out of the water for at least 24 hours.

1.1.2. 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.

14

1.1.3. NITROX

Diving with nitrox provides the diver with an opportunity to reduce the risk of
decompression illness by reducing the nitrogen content in the breathing gas mix.

However, when the gas mix is altered, the oxygen content of the mix 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 fi re or explosion hazard. Consult with
the manufacturer of your equipment about its compatibility with nitrox.

1.1.4. FREEDIVING

Freediving, and particularly freediving in combination with scuba diving, may
have risks that have not been researched and are not commonly known.

Any person who engages in any form of breathhold diving is in danger of shallow­water blackout (SWB) i.e. the sudden loss of consciousness caused by oxygen
starvation.

Any breathhold diving results in some nitrogen build-up in the blood and other
fast tissues. Due to the short time spent at depth this build-up is generally not
signifi cant. Therefore, provided the effort involved in freediving has not been

15

severe, there is little risk in diving after breathhold diving. However, the converse
is more unknown and may increase signifi cantly the risk of DCI. Therefore,
FREEDIVING AFTER SCUBA DIVING IS NOT RECOMMENDED. You
should avoid freediving and not exceed fi ve meters [16 ft] for at least two hours
after scuba diving.

Suunto also recommends you to be trained in freediving technique and physiology
before conducting breathhold dives. No dive computer can replace the need for
proper dive training. Insuffi cient or improper training may cause a diver to commit
errors that may lead to serious injury or death.

Fig. 2.1. The push buttons of the Mosquito.

16

2. GETTING ACQUAINTED

2.1. FUNCTIONS

The MOSQUITO advanced wristop computer is a multipurpose dive instrument
and a sport watch featuring several watch and dive computer modes. You can
select the dive computer model between the Regular Air Dive Computer (AIR),
Enriched Air Nitrox Dive Computer (EAN) and Freediving computer mode
(FREE). The AIR/EAN/FREE modes can also be disabled (set to OFF) and the
instrument can be used as a sports watch on land or in water.

2.2. PUSH BUTTONS

The Mosquito is controlled with four push buttons as follows (see Fig. 2.1.).

M (MODE)

• To change from a main mode to an other main mode press the mode button.

• To exit from a submode to a main mode press the mode button.

• To activate the electroluminescent backlight hold down the mode button for
more than two seconds or one second in the diving mode.

• To accept the settings in the Setting Mode press the mode button.

S (SELECT)

• To select a submode press the select button.

• To select the active segment in the Setting Mode press the select button.

• To select the display in the Logbook Mode press the select button.

17

• To select the dive planning mode in the dive surface modes.

• To make a special bookmark in the profi le memory during a dive

+, -

• To show the date, seconds or dual time in the time keeping display press
the + or - button.

• In the Setting Mode

• to increase the value press the + button

• to decrease the value press the - button.

• To operate the stopwatch see chapter 2.4.2.

• To select the dive in the Logbook Mode

• press the + button to move forward

• press the - button to move backwards.

18

2.3. WATER CONTACTS

The Mosquito is automatically activated when
submerged in water. This function is made possible by
the use of water contacts. The water contacts consist
of the PC-interface poles and the four push-buttons
of the Mosquito (Fig. 2.2). When the PC-interface
poles and one of the push-buttons are connected by
the conductivity of the water the Surface or Diving
Mode is automatically activated.

Contamination or dirt on the PC-interface poles may
prevent this automatic operation. It is, therefore,
important that the poles are kept clean. The poles
can be cleaned with fresh water and a soft brush (e.g.
tooth brush).

NOTE: Water or moisture build-up around the
wa ter contacts may cause the contact to activate auto­matically. This can happen, e.g., when washing your
hands or sweating. If the water contact activates in
the Time Mode, an AC text will appear on display
(Fig. 2.3.), and it will be shown until the water con tact
deactivates, or the Mosquito enters the Dive Mode
automatically. To save the battery power, you should
deactivate the water contact by cleaning it and/or dry­ing it with a soft towel.

Fig. 2.2. The water contact and
depth sensor.

Fig. 2.3. Active water contact is
indicated by the text AC.

19

Fig. 2.4. The Time Mode is
indicated by the TIME text and
a mode indicator.

Fig. 2.5. The time keeping display
a) the date is displayed
b) the seconds are displayed
c) the dual time is displayed.

20

2.4. TIME MODE [TIME]

The Mosquito has dual time, calendar clock, stopwatch
and alarm clock functions. The calendar clock and the
stopwatch are operated in the Time Mode. The mode is
indicated by the TIME text and the mode indicator in the
display (Fig. 2.4.). The time, dual time, date and the daily
alarm are set in the Setting Mode (see chapter 4).

2.4.1. TIMEKEEPING DISPLAY

The timekeeping display is the primary display of the
Mosquito (Fig. 2.5.). When the Time Mode is entered
from other modes, the timekeeping display activates
within two seconds, if no button is operated.

In other modes (except in the Diving or Stopwatch
Modes), if no button is operated within 5 minutes,
the Mosquito beeps and returns to the timekeeping
display automatically.

Either the date (a), the seconds of the current time
(b) or dual time (c) are shown on the bottom line
of the timekeeping display. Press the + or - button
to select the desired display option. Next time when
you enter the timekeeping display, the Mosquito will
show the selected option. The TIMER text blinks on
the display if the stopwatch is running.

The display is illuminated by holding down the M
button for more than two seconds.

To set the time and date, refer to chapter 4.1 ”Setting
Time, Date and Dual Time”.

When diving, the dive entry time and date is registered
in the Logbook Memory. Remember always to check
before diving that the time and date are correctly set,
especially when traveling to different time zones.

2.4.2. STOPWATCH [TIMER]

The Stopwatch function is entered by pressing the
S button, when the time keeping display is shown.
The text TIMEr at the bottom and the mode indicator
(TIME) on the left side of the display indicate that
you have entered the Stopwatch function (Fig. 2.6.).

The stopwatch of the Mosquito lets you measure
elapsed time, split times and the times of two runners.
The range of the stopwatch is 9 hours, 59 minutes,

59.9 seconds (Fig. 2.7.). When the range is exceeded
the computer watch gives a beep and returns to the
time keeping display automatically.

Fig. 2.6. The Stopwatch function
is indicated by the TIMEr text
and a mode indicator.

Fig. 2.7. The Stopwatch displays
hours, minutes and seconds.

21

Use the + and - buttons to operate the elapsed time measurement, split time
measurement or the times of two runners as follows:

Diving with the Mosquito or performing data transfer will stop the stopwatch.
However, it is possible to use stopwatch function when diving, if the AIR/EAN/
FREE -diving modes are disabled (set to OFF, see chapter 3.2.).

22

3. DIVING WITH THE MOSQUITO

In order to familiarize yourself with the menu based
functions, Suunto recommends you use your Quick
Reference Guide supplied with the Mosquito together
with the information in the following chapters.

This section contains instructions on how to operate
the dive computer and interpret its displays. You will
fi nd that this dive computer is easy to use and read.
Each display shows only the data relevant to that
specifi c diving situation.

Chapter 3.1. Before Diving contains general
instructions for all the dive computer modes. Chapter

3.2. Scuba Diving information for air and enriched
air nitrox scuba diving and Chapter 3.3. Free Mode
information for freediving.

Fig. 3.1. Chosen Dive Mode.

Fig. 3.2. Startup I. All segments
shown.

23

a)

3.1 BEFORE DIVING

3.1.1. ACTIVATION AND PRE-CHECKS

The instrument can be activated by pressing the M
button or it will automatically activate the air diving,
nitrox diving or freediving computer mode according
to the user selection, if submerged deeper than

b)

0.6 m (2 ft).

The chosen Dive Mode is indicated by the AIR, EAN
or FREE texts and mode indicator on the right side
of the display (Fig. 3.1.). Next, all display elements
will turn on showing mostly fi gure 8’s and graphical
elements (Fig. 3.2.). A few seconds later the battery

c)

power indicator is shown and the backlight and the
buzzer are activated (Fig. 3.3a.). Next, the screen
will display the mode dependent Ready display con­fi rming that the activation is complete (Fig. 3.4.).

At this time, perform your pre-check making sure that:

d)

24

• the Mosquito operates and provides a
complete display

• the low battery indicator is not on

• the instrument displays correct units

Fig. 3.3. Startup II. Battery power indicator.

• the instrument displays correct temperature
and depth (0.0 m [0 ft])

• the buzzer beeps

• you have preset desired displays on the User
Defi nable Display Field

• the altitude and personal adjustment settings
are correct (Air and EAN modes)

And if set to EAN mode, make sure that:

• the oxygen percentage is adjusted according
to the measured Nitrox blend in your
cylinder

• the oxygen partial pressure limit is set
correctly.

The Mosquito is now ready for diving.

NOTE: The surface interval time does not run before
the fi rst dive.

Fig. 3.5. Startup IV. Free mode. Depth and dive time are zero.
Pressing +/- button activates alternative display of maximum
depth and current time or dive number.

Fig. 3.4. Startup III. Surface
mode (Air). Depth and dive
time are zero. Pressing +/-
button activates alternative
display of maximum depth and
current time.

25

After activation of the Dive Mode or after diving, the Mosquito will automatically
switch to show the time keeping display within 5 minutes to conserve the battery
power, if you do not press any buttons. However, the dive computer functions will
remain active until it has calculated that all residual nitrogen has off-gassed. This
may take up to 100 hours, as described in chapter 7.1. ”Operating Principles”.
However, SUUNTO recommends to turn on the Dive Mode before diving to check
the settings, battery warning, etc. and for dive planning.

3.1.2. BATTERY POWER INDICATOR AND LOW BATTERY
WARNING

This dive computer has a unique graphic Battery Power Indicator designed to give
you an advance notice of impending need to change the battery.

The Battery Power Indicator can always be seen as the Dive Mode is activated. The
electroluminescent backlight will be on during the battery check. The following
Table and Figure show the various warning levels.

26

TABLE 3.1. BATTERY POWER INDICATOR

Temperature or an internal oxidation of the battery affects the battery voltage. If
the instrument is stored for a long period, the low battery warning may be displayed
even though the battery has enough capacity. The low battery warning may also
be displayed at low temperatures, even though the battery has enough capacity in
warmer conditions. In these cases repeat the battery check procedure.

27

Fig. 3.6. Low Battery Warning.
Battery symbol indicates that
the battery is low and battery
replacement is recommended.

Fig. 3.7. Bookmark activation.
An annotation, Bookmark, is
placed in the profi le memory
during a dive by pressing the
S button (Displayed with Diver
Attention symbol.).

28

After the battery check the Low Battery Warning is
indicated by the battery symbol (Fig. 3.6.).

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.

3.1.3. USER DEFINABLE FUNCTIONS
AND ALARMS

This Mosquito has several User Defi nable Functions
and depth and time related alarms that you can set
according to your personal preference. For example
the Mosquito has a patented presetting system for the
User Defi nable Display Field in the lower part of the
display.

The displays can be preset in the Surface Mode. If it is not active, enter it by
selecting the Dive Mode. The preset display will remain active until another
display is selected. The preset displays will be the default displays in the
Diving Mode. The other available display can be accessed by pressing the + or

- button. After fi ve seconds the display changes back to the default preset display
automatically.

3.1.3.1. PRESETTING TIME ALARM

The alarm clock is set in the Setting Mode, ALM. For further information see
chapter 4.2.

3.1.3.2. PRESETTING DIVE ALARMS

The dive alarms (dive time alarm and maximum depth alarm) are set in the Setting
Mode, DIVE AL. For further information see chapter 4.5.

3.1.4. BOOKMARK FUNCTION

It is possible to make special marks in the profi le memory during a dive. These
Bookmarks will be shown as a Diver Attention Symbol when scrolling the profi le
memory on the computer display (Fig. 3.7). The Bookmarks will also be shown as
annotations in the PC-software, Suunto Dive Manager. To make a bookmark on
the profi le memory during a dive press the S button. The Diver Attention Symbol
will be displayed to confi rm the bookmark.

.

29

3.2. SCUBA DIVING

3.2.1. DIVING WITH AIR

3.2.1.1. DIVE PLANNING [PLAN]

It is possible at any time in the Air/EAN Surface Mode to enter the Planning
Mode, simply by pressing the S button. After showing the text PLAN and the
mode indicator (Fig. 3.8.), the display will show the no-decompression limit for
the depth of 9 m [30 ft]. By pressing the + button, the Mosquito will calculate and
show the next deeper no-decompression limits in 3 m [10 ft] increments ending
at 45 m [150 ft] or at the maximum allowed depth in the EAN mode. By pressing
the - button the next shallower depth will be shown again.

The Planning Mode can be canceled by pressing the M or the S button.

NOTE: The Planning mode is disabled in the Air/EAN Error mode (see chapter

3.2.5.).

Higher Altitude and conservative Personal Adjustment Modes will shorten the
no-decompression time limits. These limits at different Altitude and Personal
Adjustment Mode selections are shown in Table 7.1. and 7.2.

30

The Planning mode also accounts for the following
information from previous dives:

• any calculated residual nitrogen

• all dive history for the past four days

• oxygen exposure (EAN mode)

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

DIVE NUMBERING SHOWN DURING
DIVE PLANNING

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

The surface interval must be at least 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 (see chapter 3.2.3.3.).

Fig. 3.8. Dive Planning. The
Planning mode is indicated
by the PLAN text and mode
indicators.

Fig. 3.9. Planning. The no­decompression time limit at

30.0 m [100 ft] is 18 minutes in
P0/A0 mode..

31

3.2.1.2. PRESETTING THE DISPLAYS IN
THE AIR MODE

Preset with the - button in the lower left corner of the
display (Fig. 3.4.):

Fig. 3.10. Dive has just begun.
Available no-decompression
time is more than 199 min.

Preset with the + button in the lower right corner of
the display (Fig. 3.4.):

3.2.1.3. BASIC DIVE DATA

The dive computer will remain in the Surface mode
at depths less than 1.2 m [4 feet]. At depths greater
than 1.2 m the instrument will go into the Diving
mode (Fig. 3.10.).

Fig. 3.11. Diving display. Present depth
is 19.3 m [63 ft] and no-decompression
stop time limit is 23 minutes in A0/P1
mode. Maximum depth during this dive
has been 19.8 m [65 ft], elapsed dive time
is 16 minutes. Alternative display shows
temperature and current time.

32

• the maximum depth or

• the temperature.

• the dive time or

• the current time.

During a no-decompression stop dive, the following information will be displayed
(Fig. 3.11.):

• your present depth in meters [ft]

• the Altitude Adjustment setting on the right side of the center window
with a wave and mountain symbols (A0, A1, or A2) (see Table 3.3.)

• the Personal Adjustment setting on the right side of the center window
with a diver symbol and + signs (P0, P1, or P2) (see Table 3.4.)

• the available no-decompression time in minutes in the center window as
NO DEC TIME. It is calculated based on the fi ve factors described in
chapter 7.1. ”Operating Principles”.

• the maximum depth during this dive in meters [ft], indicated as MAX or
the temperature in °C [°F] in the lower left corner.

• the elapsed dive time in minutes, indicated as DIVE TIME or the current
time, indicated as TIME in the lower right corner.

33

Fig. 3.12. A three minute
Recommended Safety Stop.

Fig. 3.13. Mandatory Safety
Stop. You are advised to make
a mandatory Safety Stop in
the zone between the ceiling
and fl oor.

34

3.2.1.4. SAFETY STOPS

Safety stops are widely considered “good diving
practice” and are an integral part of most dive tables.
Reasons to perform a safety stop include a reduction
in sub clinical DCI, microbubble reduction, ascent
control, and orientation before surfacing.

The Mosquito displays two different types of safety
stops: Recommended Safety Stop and Mandatory
Safety Stop.

The Safety Stops are indicated by:

• STOP label, when in the depth range 3 m
– 6 m [10 ft - 20 ft] = Recommended Safety
Stop Countdown which is activated when the
depth of 10 m [30 ft] is exceeded.

• STOP+ CEILING label, when in the depth
range 3 m – 6 m [10 ft - 20 ft] = Mandatory
Safety Stop Time display

• STOP label, when deeper than 6 m =
Mandatory Safety Stop scheduled

3.2.1.4.1. RECOMMENDED SAFETY STOP

With every dive over 10 meters the instrument has a three minute countdown for
the recommended safety stop, to be taken in the 3 - 6 meter [10 ft - 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 (Fig. 3.12.).

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.

3.2.1.4.2. MANDATORY SAFETY STOP

When the ascent rate exceeds 12 meters/min [40 ft] momentarily or 10 meters/min
[33ft] continuously the micro-bubble build-up is predicted to be more than 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 will depend on the severity of the ascent rate excess.

The STOP sign will appear in the display and when you reach the depth zone
between 6 m to 3 m [20 ft to 10] also the CEILING label, ceiling depth and
the calculated Safety Stop time appear in the display. You should wait until the
Mandatory Safety Stop warning disappears (Fig. 3.13.).

The Mandatory Safety Stop time always includes the three minute Recommended
Safety Stop time. The total length of the Mandatory Safety Stop time depends on
the seriousness of the ascent rate violation.

35

Fig. 3.14. Violated Mandatory
Safety Stop. Downward
pointing arrow and an audible
alarm indicate you should
descend to ceiling zone.

36

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 (Fig. 3.14.). You should immediately descend
to, or below, the Mandatory Safety Stop ceiling
depth. If you correct this situation at any time during
that dive, there are no affects on the decompression
calculations for future dives.

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.

3.2.1.5. ASCENT RATE INDICATOR

The ascent rate is shown graphically along the left side of the display as follows:

TABLE 3.2. ASCENT RATE INDICATOR

When the maximum allowed ascent rate is exceeded, the SLOW warning and the
STOP sign appear, indicating that the maximum ascent rate has been exceeded
continuously or that the current ascent rate is signifi cantly above the allowed
rate.

37

Fig. 3.15 Ascent Rate Indicator.
Blinking SLOW and four
segments are shown together
with an audible alarm: ascent
rate is more than 10 m/min
[33 ft/min]. This is a caution
to slow down! STOP sign
means that you are advised to
make a Mandatory Safety Stop
when you reach a depth of 6

38

Whenever the SLOW warning segment and the STOP
sign appear (Fig. 3.15.), you should immediately slow
down your ascent. When you reach the depth zone
between 6 m to 3 m [20 ft to 10 ft] the STOP and
CEILING depth labels will advise you to make a
Mandatory Safety Stop. Wait until the warning
disappears (Fig. 3.13.). You should not ascend
shallower than 3 m [10 ft] with the Mandatory Safety
Stop warning on.

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).

3.2.1.6. DECOMPRESSION DIVES

When your NO DEC TIME becomes zero, your dive becomes a decompression
stop dive, i.e. you must perform one or several decompression stops on your way
to the surface. The NO DEC TIME on your display will be replaced by a CEILING
and blinking ASC TIME notation and an upward pointing arrow (Fig. 3.17.).

If you exceed the no-decompression limits on a dive, the dive computer will
provide 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 fi xed depths, the dive computer gives
you the option to decompress with a more gradual and natural series of mini steps
within the decompression range (continuous decompression).

Fig. 3.16. Ceiling, ceiling zone,
fl oor and decompression range.

39

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

• time needed to ascend to the ceiling at an ascent rate of 10 m/min [33
ft/min] plus

• time needed at the ceiling. The ceiling is the shallowest depth where
decompression could be made plus

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

• 3 minute Recommended Safety Stop plus

• time needed to reach the surface after the ceiling and safety stops have
been completed.

WARNING

Your ascent time may increase if you:

- ascend slower than 10 m/min [33 ft/min] or

- make your decompression stop deeper than at the ceiling.

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

40

CEILING, CEILING ZONE, FLOOR AND DECOMPRESSION RANGE

When in decompression, it is important that you understand the meaning of
ceiling, fl oor, and decompression range (Fig. 3.16.):

• The ceiling is the shallowest depth where decompression could be made.
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 1.8 m [6 ft] below the minimum
ceiling.

• The fl oor 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
fl oor. Within this range, decompression takes place. However, it is
important to remember that the decompression will be very slow at, or
close to, the fl oor.

The depth of the ceiling and fl oor will depend on your dive profi le. 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 fl oor and ceiling may change upwards while you are decompressing.

41

When conditions are rough, it may be diffi cult to
maintain a constant depth near the surface. In this
case it will be more manageable to maintain an
additional distance below the ceiling, to make sure
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

Fig. 3.17. Decompression dive,
below fl oor. Upward pointing
arrow, blinking ASC TIME
label and an audible alarm tell
you to ascend. Minimum total
ascent time including safety
stop is 7 minutes. Ceiling is at
3 m [10 ft].

is shallower.

NOTE: It will take more time and more gas to
decompress below the ceiling than at the ceiling.

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.

Fig. 3.18. Decompression dive, above fl oor.
Upward pointing arrow has disappeared and
ASC TIME label has stopped blinking, which
means that you are in the decompression range.

42

WARNING

DISPLAY BELOW THE FLOOR
The blinking ASC TIME and an upward pointing

arrow indicate that you are below the fl oor (Fig. 3.17.).
You should start your ascent immediately. The ceiling
depth is shown on the left and the minimum total ascent
time on the right side of the center window.

DISPLAY ABOVE THE FLOOR
When you ascend above the fl oor, the ASC TIME

display stops blinking and the upward pointing
arrow disappears. (Fig. 3.18.) Decompression will
now begin, but is very slow. You should therefore
continue your ascent.

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, Fig. 3.19.). Do not ascend above this zone.

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

Fig. 3.19. Decompression
dive, at ceiling zone. Two
arrows point at each other
(“hour glass”). You are in the
optimum ceiling zone at 3.5
m [11 ft] and your minimum
ascent time is 5 minutes.

43

Fig. 3.20. Decompression dive,
above ceiling. Note downward
pointing arrow, Er warning and
an audible alarm. You should
immediately (within 3 minutes)
descend to or below ceiling.

44

only after the ASC TIME and CEILING labels have
disappeared, which means that the

decompression stop
and any Mandatory Safety Stop has been completed.
You are advised, however, to stay until the STOP sign
has also gone. This indicates that the three 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 (Fig. 3.20.). In addition,
an error warning Er reminds you that you have only
three minutes to correct the situation. You must
immediately descend to or below the ceiling.

If you continue to violate the decompression, the
dive computer goes 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 (see chapter 3.2.5.).

3.2.2. DIVING WITH EAN (NITROX)

3.2.2.1. BEFORE DIVING

This dive computer can be set for diving with standard air only (Air mode) or it
can be set for diving with Enriched Air Nitrox (EAN mode).

If set to the EAN 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 according to the entered O
based on Nitrox result in longer no-decompression times and shallower maximum

% value (Fig. 3.21.). Calculations

2

depths.

The EAN mode is set using the SET DIVE function (See Chapter 4.3 Dive Mode
Settings)

DEFAULT NITROX SETTINGS

In the EAN mode, the default setting is for standard air (21% O2). It remains in this
setting until the O2% is adjusted to any other percentage of oxygen (22% - 50%).

If a dive is started within 2 hours Mosquito retains this value until the dive series
is fi nished. If unused, the computer will retain the manually entered value for the
selected oxygen percentage for about two hours, after which it will revert to the
default setting of 21% O

.

2

The default setting for maximum oxygen partial pressure is 1.4 bar, however you
are able to set it in the range of 1.2 - 1.6 bar.

45

Fig. 3.21. Nitrox display.
Maximum depth based on set
O2% (21%) and PO2 (1.4 bar)
is 54.1 m [177 ft].

Fig. 3.22. Diving in EAN mode.
The O

% is set to 32%. PO2 is

2

0.9. Alternative displays are
maximum depth, temperature,
dive time and time.

46

3.2.2.2. PRESETTING THE DISPLAYS IN
THE EAN MODE

When entering the EAN mode the oxygen percentage
and partial pressure are always the default displays in
the lower part of the display.

Preset with the - button in the lower left corner of the
display (Fig. 3.22.):

• oxygen percentage (default)

• the maximum depth or

• the temperature.

Preset with the + button in the lower right corner of
the display (Fig. 3.22.):

• current oxygen partial pressure

• the dive time or

• the current time.

3.2.2.3. OXYGEN DISPLAYS

If set to EAN mode the NITROX display, with all
labeled oxygen information, is shown immediately after
activation. The nitrox display shows (Fig. 3.21.):

• oxygen percentage, labeled with O2%, is
shown in the left side of the lower display

• set oxygen partial pressure limit, labeled

, is shown in the right side of the

with PO

2

lower display

• maximum allowed depth based on the set
oxygen percentage and partial pressure limit

• current oxygen toxicity exposure shown
with an Oxygen Limit Fraction (OLF) bar
graph along the right side of the display.

In the Dive mode the current oxygen toxicity exposure
is always shown with an Oxygen Limit Fraction
(OLF) bar graph and the oxygen percentage labeled
with O2%. The current oxygen partial pressure labeled
with PO2is also shown, if selected (Fig. 3.22.). During
a dive, the oxygen partial pressure, labeled with PO
is always shown instead of the preselected display, if

2

the partial pressure is greater than 1.4 bar or the set
value (Fig. 3.23.).

Fig. 3.23. Oxygen partial
pressure and OLF displays.
There is an audible alarm and
the last segment of the bar graph
starts to blink as oxygen partial
pressure is greater than 1.4 bar
or set value, and/or the OLF has
reached 80% limit. When OLF
has reached 100%, all segments
starts to blink. If the OTU value
is higher than the CNS value, the
lowest segment blinks.

,

47

3.2.2.4. OXYGEN LIMIT FRACTION (OLF)

In addition to tracking the diver’s exposure to nitrogen, 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) bar graph has 7 segments, each representing
12,5% (from 1 to 50%) or 15% (from 50% to 80%). The OLF bar graph displays
only the value of the higher of the two calculations. When the OTU value meets
and exceeds the CNS value then in addition to displaying its percentage the lowest
segment blinks to indicate that the value shown relates to OTU. The oxygen
toxicity calculations are based on the factors listed in chapter 7.3. “Oxygen
Exposure”.

48

3.2.3. AT THE SURFACE

3.2.3.1. SURFACE INTERVAL AFTER AN AIR/EAN DIVE

An ascent to any depth shallower than 1.2 m [4 ft] will cause the DIVING display
to be replaced by the alternating SURFACE displays, giving the following
information (Fig. 3.24. and 3.25.):

• maximum depth of most recent dive in meters [ft]

• present depth in meters [ft]

• the surface time in hours and minutes (separated by a colon), telling the
duration of the present surface interval

• the desaturation/no-fl ying time in hours and minutes is shown next to
the airplane in the center window of the display

• no-fl ying warning indicated by an airplane icon

• Altitude Adjustment setting

• Personal Adjustment setting

• Diver Attention symbol indicates if you should prolong your surface
interval time

• STOP label for 5 min, if the Mandatory Safety Stop was violated

• ASC TIME, if the decompression ceiling was violated (= Error Mode)
(Fig. 3.26.)

49

Fig. 3.24. Surface display.
You have surfaced from a 18
minute dive, which maximum
depth was 20.0 m [66 ft]. The
present depth is 0.0 m [0 ft]
and surface interval time is 0.
Airplane symbol indicates that
you should not fl y and diver
attention symbol indicates that
you should prolong your surface
interval time because of excess
micro-bubbles.

50

Or in the lower display according the selection and
mode:

• dive time of most recent dive in minutes
labeled with DIVE TIME.

• the current time labeled with TIME

• oxygen partial pressure labeled with PO
set to EAN mode)

• maximum depth labeled with MAX

• the current temperature with °C for
Centigrade [or °F for Fahrenheit]

• oxygen percentage setting labeled with O2%
(if set to EAN mode)

If set to EAN mode, the current oxygen toxicity
exposure is shown with an Oxygen Limit Fraction
(OLF) bar graph along the right side of the display.

Fig. 3.25. Surface display.
Alternating display showing
the no-fl ying time.

2

(if

3.2.3.2. DIVER ATTENTION SYMBOL

The Diver Attention Symbol is an advice to extend
surface interval. Some patterns of diving, in particular
multiday diving with many dives and short surface
intervals, cumulatively add a higher risk of DCI.
When this is detected in addition to adapting the
decompression algorithm, the Diver Attention
Symbol is shown.

3.2.3.3. DIVE NUMBERING

Several repetitive dives are considered to belong to the
same repetitive dive series when the dive computer
has not counted the no-fl ying time to zero. Within
each series, the dives are given individual numbers.
The fi rst dive of the series will be numbered as DIVE
1, the second as DIVE 2, the third as DIVE 3, etc.

If you start a new dive with less than 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

Fig. 3.26. Surface Mode after
a violated decompression dive.
ASC TIME symbol indicates
that you have violated the ceiling
for more than three minutes. The
alternating display shows you
that you must not dive again for
at least 48 hours.

51

the dive time will begin where it left off. After 5 minutes on the surface, subsequent
dives are, by defi nition, repetitive. The dive counter displayed in the Planning
Mode will increment to the next higher number if another dive is made.

3.2.3.4. FLYING AFTER DIVING

The no-fl ying time is shown in the center window next to the airplane image.
Flying or travelling to a higher altitude should be avoided at any time the computer
counts down the no-fl ying time.

The no-fl ying time is always at least 12 hours or equivalent to the so-called
desaturation time (if longer than 12 hours).

In the permanent Error mode the no-fl ying time is 48 hours.

Divers Alert Network (DAN) recommends the following on no-fl ying 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 2400 m [8000 ft]).

• 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 fl ight. Further,
the Undersea and Hyperbaric Medical Society (UHMS) suggests divers
using standard air tanks and exhibiting no symptoms of decompression
illness wait 24 hours after their last dive to fl y in an aircraft with cabin
pressure up to 2400 m [8000 ft]. The only two exceptions to this
recommendation are:

52

• If a diver had less than 2 hours total accumulated dive time in the last 48
hours, then a 12 hour surface interval before fl ying is recommended.

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

• Suunto recommends that fl ying is avoided until all the DAN and UHMS
guidelines and the dive computer wait to fl y conditions are satisfi ed.

3.2.4. HIGH ALTITUDE DIVES AND PERSONAL
ADJUSTMENT

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

3.2.4.1. ALTITUDE ADJUSTMENT

When programming the instrument for the correct altitude, you need to select the
correct Altitude Mode according to Table 3.3. The dive computer will adjust its
mathematical model according to the entered altitude mode, giving shorter no­decompression times at higher altitudes (see chapter 7.1., Table 7.1. and 7.2.).

53

TABLE 3.3. ALTITUDE ADJUSTMENT RANGES

The entered Altitude Adjustment Mode is indicated by mountain symbols (A0,
A1 = one mountain, or A2 = two mountains). Also, the maximum altitudes are
displayed for each Altitude group (see Table 3.3.). Chapter 4.6. describes how the
Altitude Mode is adjusted.

Traveling to a higher elevation can temporarily cause a change in the equilibrium
of dissolved nitrogen in the body. It is recommended that you acclimate to the new
altitude by waiting at least three hours before making a dive.

54

3.2.4.2. PERSONAL ADJUSTMENT

There are adverse personal factors for DCI which divers can predict in advance
and input into the decompression model. Factors that may affect susceptibility to
decompression illness vary between divers and also for the same diver from one
day to another. The three-step Personal Adjustment Mode is available, if a more
conservative 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]

• the diver is below average physical fi tness level

• diver fatigue

• diver dehydration

• previous history of DCI

• stress

• obesity

The Personal Adjustment Mode is indicated by a diver symbol and plus signs (P0
= a diver, P1 = diver +, or P2 = diver ++). Chapter 4.6. describes how the Personal
Mode is adjusted.

55

This feature should be used to adjust the computer to be more conservative,
according to personal preference, by entering the suitable Personal Adjustment
Mode with the help of Table 3.4. In ideal conditions, retain the default setting, P0.
If conditions are more diffi cult or other mentioned factors which tend to increase
the possibility of DCI exist, select P1 or even the most conservative P2. As a
result the dive computer adjusts its mathematical model according to the entered
Personal Adjustment Mode, giving shorter no-decompression times (see chapter

7.1., Table 7.1. and 7.2.).

TABLE 3.4. PERSONAL ADJUSTMENT RANGES

56

3.2.5. ERROR CONDITIONS

The dive computer has warning indicators that alert the user to react to certain
situations that would signifi cantly increased 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 dive sensibly, it is very unlikely you will
ever put the instrument into the Error Mode.

OMITTED DECOMPRESSION
The Error Mode results from omitted decompression, i.e. 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 will
enter a permanent Error Mode. The instrument will continue to function normally
if you descend below the ceiling within this three-minute period.

Once in the permanent Error Mode only the Er warning is shown in the center
window. The dive computer will not show times for ascent or stops. However, all
the other displays will function as before to provide information for ascent. You
should 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.

The Error mode will stay for 48 hours, during which time you should not dive.
Whilst Mosquito is in Error mode the ASC TIME label will be displayed in the
center window and the Planning Mode will be disabled.

57

Fig. 3.27. Free Mode.

Fig. 3.28. Surface display/
Alternative displays.

58

3.3. FREEDIVING

3.3.1. BEFORE DIVING IN THE FREE
MODE

If set to Free mode, the dive computer can be used for
freediving or snorkeling. In the freediving mode the
Mosquito provides depth, time and profi le information
and an accurate 2 second sampling interval for the
logbook profi le memory

The Free mode is set using the SET DIVE function
(See Chapter 4.3 Dive Mode Settings)

If set to Free mode the text FREE is shown after
activation (Fig. 3.27.)

3.3.2. PRESETTING THE DISPLAYS IN
THE FREE MODE

The information shown in the Free mode can be preset
before the dive.

Preset with the - button in the lower left corner of the
display (Fig. 3.28.)

• the maximum depth or

• the temperature.

Preset with the + button in the lower right corner of
the display (Fig. 3.28.)

• the dive time,

• the current time or

• the dive number.

3.3.3. DURING THE FREEDIVE

In the Freediving mode the present depth is always
shown. Maximum depth, temperature, dive time,
current time and dive number are shown in the
alternative displays.

In addition to the Dive Time display in the lower right
corner of the display, the Free Dive Time in minutes
and seconds is shown in the center window (Fig.

3.29.) By pressing the S button you get a bookmark
in the dive profi le.

3.3.4. FREEDIVING DAY HISTORY

It is possible at any time in the Free Surface Mode to
enter the Freediving Day History Mode, simply by
pressing the S button. After showing the text DAY
HIS and the mode indicator (Fig. 3.30.), the display
will show (Fig. 3.31.):

Fig. 3.29. Freedive. Present
depth is 6.1 m, dive time 1.03
min and dive number is 1.

Fig. 3.30. Freediving Day
History.

59

m

DIVE

Fig. 3.31. Day History display.

m

DIVETIME

°C

Fig. 3.32. Display after
exceeding the 5min freediving
time limit. Flashing Er and
upward arrow.

60

• the total amount of free dives,

• the longest free dive in minutes and seconds
in the center window and

• the deepest free dive made during that day.

The Day His Mode can be canceled by pressing the

M or the S button.

3.3.5. EXCEEDING THE FREEDIVING
TIME LIMIT

To prevent the possibility of accidentally using the
Free-mode during a SCUBA dive the Free mode is
limited to 5 minutes. If the 5 minute limit is exceeded
the user is warned by an audible alarm, activated
backlight, upward arrow and a blinking error
warning Er. After 6 minutes in the Free mode the
Mosquito goes into Error mode, and the Er warning
is permanently displayed (Fig. 3.32).

NOTE: The Free mode is limited to 5+1 minutes.
If the limit is exceeded the computer goes into Error
mode. In Error mode the computer can not be used as
a dive computer for 48 hrs.

3.3.6. SURFACE INTERVAL AFTER A
FREEDIVE

An ascent to any depth shallower than 1.2 m [4 ft]
will cause the DIVING display to be replaced by the
SURFACE display, giving the following information
(Fig. 3.33.):

• maximum depth of most recent dive in
meters [ft]

• present depth in meters [ft]

• the surface time in minutes and seconds
(separated by a colon), telling the duration
of the present surface interval. After one
hour the surface time is displayed in hours
and minutes.

NOTE: Dive numbering in the Free mode is different
than in the Air/EAN mode. It is based on repetitive
dives made during one day. The dive number is
zeroed at midnight.

Fig. 3.33. Surface display
after Freedive. Center window
showing surface time.

61

3.4. AUDIBLE AND VISUAL ALARMS

The dive computer features audible and visual alarms to advise when important
limits are approached or to acknowledge preset alarms.

A short single beep occurs when:

• the dive computer automatically returns to the Time mode.

Three single beeps with a two second interval and the backlight when:

• the no-decompression dive turns into a decompression stop dive. An
arrow pointing upwards and the blinking ascent warning ASC TIME
will appear (Fig. 3.17.).

Continuous beeps and the backlight activated when:

• the maximum allowed ascent rate, 10 m/min [33 ft/min], is exceeded.
SLOW and STOP warnings will appear (Fig. 3.15.).

• the Mandatory Safety Stop ceiling is exceeded. A downward pointing
arrow will appear (Fig. 3.14.).

• the decompression ceiling depth is exceeded. An error warning Er and a
downward pointing arrow appear. You should immediately descend to, or
below, the ceiling. The instrument will otherwise enter a permanent Error
Mode within three minutes, indicated by a permanent Er (Fig. 3.20.).

• the 5 minute time limit in Freediving mode is exceeded. An error
warning Er and a upward pointing arrow will appear. After 5+1 minutes
the Mosquito goes into Error mode (Fig. 3.32).

62

You are able to preset alarms before the actual dive. The user programmable
alarms can be set for maximum depth, dive time and daily time. The alarms
activate when:

• The preset maximum depth is reached

• continuous beep series for 24 seconds or until any button is pressed.

• the maximum depth blinks as long as the present depth value
exceeds the adjusted value.

• The preset dive time is reached

• continuous beep series for 24 seconds or until any button is pressed.

• the dive time blinks for one minute, if no button is pressed.

• The preset alarm time is reached

• the current time is shown.

• continuous beep series for 24 seconds or until any button is pressed.

• the current time blinks for one minute, if no button is pressed.

OXYGEN ALARMS IN EAN MODE

Three double beeps and the backlight activated when:

• the OLF bar graph reaches 80%. The segments exceeding the 80% limit
start to blink (Fig. 3.23.)

• the OLF bar graph reaches 100%. All the OLF bar graph segments start
to blink.

The blinking of the segments will stop when the OLF is not loading anymore. At
that point the PO

is less than 0.5 bar.

2

63

Continuous beeps for 3 minutes and the backlight activated occur when:

• the set oxygen partial pressure limit is exceeded. The maximum depth is
replaced with the current blinking PO
ascend above the PO2depth limit (Fig. 3.23.).

value. You should immediately

2

WARNING

When the oxygen limit fraction indicates that the maximum limit is reached,
you must immediately ascend until the warning stops blinking! Failure to
take action to reduce oxygen exposure after the warning is given can rapidly
increase the risk of oxygen toxicity and the risk of injury or death.

64

4. SETTING MODE [SET]

The time, date, dual time, daily alarm, scuba and
free dive selections and settings, dive time and depth
alarms and the altitude, personal and unit adjustments
are set in the Setting Mode (Fig. 4.1.).

Enter the Setting Mode from other modes by pressing
the M button. The text SET at the bottom and the
mode indicator on the left side of the display indicate
the selected mode

4.1. SETTING TIME, DATE AND
DUAL TIME [TIME ]

To set the time and date:

1. In the Setting Mode, press S to select the Time
Adjustment Mode (Fig. 4.2.).

2. Wait two seconds until the Time Adjustment
Mode activates automatically. The time mode
indicator appears and the second digits start to blink
on the display (Fig. 4.3.).

Fig. 4.1. The Setting Mode is
indicated by the SET text and
mode indicator.

Fig. 4.2. Time Adjustment
Mode.

65

Fig. 4.3. The Time Adjustment
Mode is activated and the second
digits are blinking. Page I.

Fig. 4.4. The year, month and
day is selected. Page II. Dual
time selected. Page III.

66

3. Press S to change the selection in the following
sequence:

-

> seconds -> hours -> minutes -> 12/24 hour format

-

> year -> month -> day -> dual (home) time hours

-

> minutes

4. While the second digits are selected (blinking),
press - to reset the seconds to ”00” or press + to
increase the value.

5. While any other digits (except seconds) are
selected (blinking), press + to increase the value or ­to decrease it. Holding the button the current selection
starts to scroll.

6. After you have set the time and date, press the M
button to save the settings and to return to the Setting
Mode [SET].

NOTE:

• The day of the week is automatically calculated in
accordance with the date.

• The date can be set within the range of Jan 1, 1990
to Dec. 31, 2089.

NOTE:

• While the selection is blinking and no button is
operated within 10 minutes, the blinking stops and
the Mosquito beeps and returns automatically to the
timekeeping display.

• The display is illuminated by holding down the M
button for more than two seconds.

4.2. DAILY ALARM SETTING [ALM]

You can set one daily alarm in the Mosquito. When
the daily alarm activates, the -symbol blinks for
1 minute and the alarm sounds for 24 seconds. The
alarm is given at the preset time each day. Press
any button to stop the audible alarm, after it has
activated.

To set the daily alarm:

1. In the Setting Mode, press S two (2) times to select
the Daily alarm Setting Mode (Fig. 4.5.).

2. Wait two seconds until the Daily Alarm Setting
Mode activates automatically. The time mode
indicator appears and the alarm status [On/OFF]
starts to blink on the display (Fig. 4.6.).

Fig. 4.5. Daily alarm Setting
Mode.

Fig. 4.6. Daily Alarm Setting
Mode is activated.

67

3. Press S to change the selection in the following sequence:

-

>On/OFF status -> hours -> minutes

4. While the alarm status [On/OFF] is selected (blinking) press + or - to change
the status. When the alarm status is On, the daily alarm indicator ( -symbol) in
the bottom right corner of the display indicates that the alarm is on.

5. Set the other sections as follows:

• While any other digits (except alarm status) are selected (blinking), press + to
increase the value or - to decrease it. Holding down either button starts the scrolling
of the current selection.

• The 12-hour or 24-hour format of the alarm matches the format of the
timekeeping display, which is selected in the Time Adjustment Mode (see
chapter 4.1.). When using the 12-hour format of the alarm, take care to set the
time correctly as morning (AM) or afternoon (PM).

6. After you have set the daily alarm, press the M button to save the settings and
to return to the Setting Mode [SET].

68

4.3. DIVE MODE SETTINGS [DIVE]

In this mode you can select the type of dive mode to be
used (Air, Nitrox or Free) or turn the dive modes OFF.
If the dive modes are turned OFF, the dive computer
functions are disabled, thus turning the Mosquito into
a mere water resistant sportswatch.

NOTE: If the DIVE mode is disabled (set to OFF), the
instrument will not activate the selected diving mode
(Air, EAN, Free) when submerged.

4.3.1. SET AIR MODE

To set the Air mode:

1. In the Setting Mode, press S three (3) times to
select the Dive Setting Mode (Fig. 4.7.).

2. Wait two seconds until the Dive Setting Mode
activates automatically. The enable/disable status
[On/OFF] starts to blink on the display and the
selected dive mode (AIR, EAN or FREE) is displayed
(Fig. 4.8.)

While the enable/disable status [On/OFF] is selected
(blinking) press + or - to change the status.

Fig. 4.7. Dive Setting Mode.

Fig. 4.8. Set Air/EAN/Free
Mode. Enable/disable status
blinks.

69

Fig. 4.9. Setting Oxygen
Percentage and Partial Pressure
(EAN mode only).

70

3. Press S to change the selection in the following
sequence:

-

>On/OFF status -> AIR/EAN/FREE mode

When the AIR/EAN/FREE dive mode is selected
(blinking) press + or - to change the mode to AIR.

4. After you have set the AIR mode, press the M
button to save the settings and to return to the Setting
Mode [SET].

4.3.2. SET EAN MODE

If set to the EAN (Nitrox) 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. Also in EAN mode, the oxygen partial pressure limit must
be set. When in the EAN Setting mode the equivalent allowed maximum depth
based on the chosen setting will also be displayed.

To set the EAN mode:

1. In the Setting Mode, press S three (3) times to select the Dive Setting Mode
(Fig. 4.7.).

2. Wait two seconds until the Dive Setting Mode activates automatically. The
enable/disable status [On/OFF] starts to blink on the display and the selected dive
mode (AIR, EAN or FREE) is displayed (Fig. 4.8.)

While the enable/disable status [On/OFF] is selected (blinking) press + or - to
change the status.

3. Press S to change the selection in the following sequence:

-

>On/OFF status -> AIR/EAN/FREE mode-> if EAN selected: Oxygen percentage

%)-> Oxygen partial pressure (PO2)

(O

2

When the dive mode is selected (blinking) press + or - to change the mode to
EAN.

4. Press S to access the Oxygen percentage (O
(PO

) settings.

2

%) and Oxygen partial pressure

2

71

When Oxygen percentage (O2%) or Oxygen partial pressure (PO2) are selected
(blinking) press + or - to change the setting (Fig. 4.9.).

5. After you have set the EAN settings, press the M button to save the settings
and to return to the Setting Mode [SET]

4.3.3. SET FREE MODE

To set the FREE mode:

1. In the Setting Mode, press S three (3) times to select the Dive Setting Mode
(Fig. 4.7.).

2. Wait two seconds until the Dive Setting Mode activates automatically. The
enable/disable status [On/OFF] starts to blink on the display and the selected dive
mode (AIR, EAN or FREE) is displayed (Fig. 4.8.)

While the enable/disable status [On/OFF] is selected (blinking) press + or - to
change the status.

3. Press S to change the selection in the following sequence:

->On/OFF status -> AIR/EAN/FREE mode

When the dive mode is selected (blinking) press + or - to change the mode to
FREE.

4. After you have set the FREE, press the M button to save the settings and to
return to the Setting Mode [SET].

72

4.4. DIVE ALARM SETTINGS
[DIVE AL]

You can set one depth alarm in the Mosquito. When
the depth alarm activates, the -symbol blinks as long
as the present depth value exceeds the adjusted value
and the alarm sounds for 24 seconds. Press any button
to stop the audible alarm, after it has activated.

To set the depth alarm:

1. In the Setting Mode [SET], press S four (4) times
to select the Dive Alarm Setting Mode (Fig. 4.10.).

2. Wait two seconds until the Dive Alarm Setting
Mode activates automatically. The alarm status [On/
OFF] starts to blink on the display (Fig. 4.11.).

3. Press S to change the selection in the following
sequence.

->On/OFF status -> depth alarm limit -> dive time
alarm minutes (-> dive time alarm seconds)

Fig. 4.10. Dive Alarm Setting
Mode.

Fig. 4.11. Dive Time Alarm.
Center window displays less
than 5 minutes dive time.

73

Fig. 4.12. Dive Time Alarm.
Display when more than 5
minutes dive time left.

74

4. While the alarm status [On/OFF] is selected
(blinking), press + or - to change the status. When
the alarm status is On, the depth alarm indicator
( -symbol) in the bottom right corner of the display
indicates that the alarm is on.

5. While the depth digits are selected (blinking), press
+ to increase the value or - to decrease it at intervals
of 0.5 m [1 ft]. Holding down either button starts the
scrolling of the depth value. The range of the depth
is from 3.0 to 99.5 m [10 to 300 ft]. If set to 0, the
alarm is disabled.

6. While the dive time minutes are selected (blinking),
press + or - to change the time. If the time is less than
fi ve (5) minutes, the dive time alarm seconds can
also be set. This feature can be used for freediving
(Fig. 4.11.). If the selected time is over 5 minutes no
seconds are displayed (Fig. 4.12.).

7. After you have set the depth alarm, press the M
button to save the settings and to return to the Setting
Mode [SET].

4.5. ALTITUDE, PERSONAL AND
UNIT ADJUSTMENT SETTINGS
[AdJ]

The current Altitude and Personal Adjustment Modes
are shown when diving as well as at the surface. If the
mode does not match the altitude or conditions (see
chapter 3.2.4.), it is imperative that the diver enters
the correct selection before diving. Use the Altitude
Adjustment to select the correct altitude mode. Use
the Personal Adjustment to add an extra level of
conservatism. In this setting mode also the desired units
can be selected (metric, m/°C or imperial, ft/°F).

NOTE: New altitude and personal adjustment
selections cannot be made until 5 minutes after a
scuba dive.

To set the new Altitude, Personal or Unit Adjustments:

1. In the Setting Mode [SET], press S fi ve (5) times
to select the Altitude, Personal and Unit Adjustment
Mode (Fig. 4.13.).

2. Wait two seconds until the Adjustment Mode
activates automatically. The altitude setting starts to
blink on the display (Fig. 4.14.).

Fig. 4.13. Adjustment Mode.

Fig. 4.14. Setting Altitude
Adjustment.

75

Fig. 4.15. Setting Personal
Adjustment.

Fig. 4.16. Setting metric/
imperial units.

76

3. Press S to change the selection in the following
sequence.

-

>altitude adjustment -> personal adjustment -> units

4. While the altitude digits are selected (blinking), press
+ or - to change the Altitude Mode (Fig. 4.16.).

5. While the personal adjustment digits are selected
(blinking), press + or - to change the Personal
Adjustment Mode (Fig. 4.15.).

6. While the units are blinking in the lower part of the
display, press + or - to change units (Fig. 4.16.).

7. After you have set the desired adjustments, press
the M button to save the settings and to return to the
Setting Mode [SET] ).

WARNING

Always recheck the personal and altitude
adjustment to ensure that the altitude is not set
for an altitude less than that of the dive site and
that the personal mode corresponds to the desired
conservatism. Failure to enter this information
could result in dive planning errors and risk
exposure to decompression sickness.

5. MEMORIES AND DATA
TRANSFER [MEM]

The memory functions for the Mosquito include the
combined Logbook and Dive Profi le Memory, Dive
History Memories for scuba and free dives and the
Data Transfer and PC-Interface functions.

NOTE: After scuba diving, the memory mode cannot
be accessed until 5 minutes after the dive.

Enter the Memory Mode [MEM] from other modes
by pressing the M button. The text MEM at the
bottom and the mode indicator on the left side of the
display indicate the selected mode (Fig. 5.1.).

If any button is not operated within 5 minutes after
a function of the Memory Mode is selected, the
Mosquito beeps and returns to the timekeeping
display automatically.

Fig. 5.1. Memory Mode.

77

Fig. 5.2. Logbook memory
mode

78

5.1. LOGBOOK AND DIVE PROFILE
MEMORY [LOG]

This instrument has a sophisticated high capacity
Logbook and Profi le Memory. The data is recorded
to the profi le memory based on the sampling rate. The
sampling rate in Air/EAN mode is 20 s, and in Free
mode 2 s. Dives shorter than the recording interval
are not registered.

To enter the Logbook Memory Mode:

1. In the Memory Mode [MEM], press S to select the
Logbook Memory Mode (Fig. 5.2.). The LOG text
appears at the bottom of the display to indicate the
selected mode.

2. Wait two seconds until the Logbook Memory
Mode activates automatically. For each dive there
are four pages of logbook dive information.

3. Press S to switch the display between Logbook
display I, II, III and IV.

The data of the most recent dive is shown fi rst. The
END text is displayed after the oldest and most recent
dive. (Fig. 5.7.)

Note that chronological sequence in the logbook is
determined by the date, not by the dive number.

The following information will be shown on four
pages:

Page I, main display (Fig. 5.3.)

• dive number in the dive series, Air/EAN
dives are indicated by a D number and
Freedives by a F number

• dive entry time and date.

Page II (Fig. 5.4.)

• maximum depth

(NOTE: Due to lower resolution, the

reading may differ from the maximum
depth reading of the Dive History or surface
display up to 0.3 m [1 ft].)

• total dive time

• Altitude Adjustment setting (not displayed
in Free mode)

• Personal Adjustment setting (not displayed
in Free mode)

• Blinking SLOW, if the diver has violated the
maximum ascent rate

• STOP label, if the Mandatory Safety Stop
was violated

Fig. 5.3. Logbook, page I.

Fig. 5.4. Logbook, page II.
Main dive related data.

79

Fig. 5.5. Logbook, page III.
Surface interval time, average
depth.

Fig. 5.6. Logbook, page IV.
Profi le of specifi c dive.

80

• ASC TIME label, if the dive was a
decompression stop dive

• Diver attention symbol, if the dive was
started while symbol was displayed

• downward pointing arrow, if the ceiling was
violated

• oxygen percentage (only for nitrox dives)

• maximum OLF during the dive (only for
nitrox dives).

Page III (Fig. 5.5.)

• average depth

• surface interval time before the dive

• temperature at the maximum depth

Page IV (Fig. 5.6.)

• the profi le of the dive, automatic scrolling
during which:

• blinking diver attention symbol when the
user has pressed the S button for Bookmark

• blinking SLOW and STOP label when
registered

• blinking ASC TIME label when the dive
became a decompression dive.

The data of the most recent dive is shown fi rst. Press

- to call the information from the previous dive. Press
the - button consecutively to move backward through
the dives. Press + to move forward through the dives.
It is possible to scroll trough the dives on all four
pages. The END text is displayed after the oldest and
the most recent dive (Fig. 5.7.).

The memory will always retain approximately the
last 36 hours of dive time in Air/EAN mode and
approximately 2 hours in freediving mode. After
that, when new dives are added, the oldest dives
are deleted. The contents of the memory will remain
even when the battery is changed (assuming that
the replacement has been done according to the
instructions).

DIVE PROFILE MEMORY [PRO]
The scrolling of the profi le will start automatically

when the Profi le/logbook page IV is entered (Fig.

5.6.).

The dive time is displayed in sampling increments
with each display being shown for about three
seconds. The depths shown are the maximum values
of each sampling interval.

Fig. 5.7. Logbook, end of the
memory. END text is displayed
between oldest and the most
recent dive.

81

After the last depth fi gure of the selected profi le, the Mosquito automatically
returns to Display I of the same dive in the Logbook. If desired, the profi le of the
same dive can be recalled again following the above procedure.

The scrolling of the profi le can be stopped by pressing any button.

• Press S to stop the scrolling and to return to Display I of the same dive
in the Logbook.

• Press + to stop the scrolling and to change to scrolling the next dive in
the Logbook.

• Press - to stop the scrolling and to change to scrolling the previous dive
in the Logbook.

• Press M to stop the scrolling and to return to the beginning of the
Logbook.

• Press M two (2) times to exit the Logbook Memory [LOG] and enter the
Memory Mode [MEM].

NOTE: Several repetitive dives are considered to belong to the same repetitive
dive series if the no-fl ying time has not ended. See ”Dive Numbering” in chapter

3.2.3.3. for further information.

82

5.2. DIVE HISTORY MEMORY [HIS]

The Dive History is a summary of all the scuba and
free dives recorded by the Mosquito. Scuba and
Freediving histories are kept separate. To enter the
Dive History Memory Mode:

1. In the Memory Mode [MEM], press S two (2)
times to select the Dive History Memory Mode
(Fig. 5.8.). The HIS text appears at the bottom of the
display to indicate the selected mode.

2. Wait two seconds until the Dive History Memory
Mode activates automatically. The following scuba
dive information will be shown on the display
(Fig. 5.9.):

• the maximum depth ever reached

• the total accumulated dive time in hours

• the total number of dives.

The scuba dive history is indicated by a D on the
lower left of the display.

999 dives and 999 hours of diving can be registered.
When these maximum values are reached, the
counters will start again from 0.

Fig. 5.8. Dive History Memory.

Fig. 5.9. Scuba Dive History
Memory. Total number of
dives, dive hours and maximum
depth.

83

Fig. 5.10. Free dive History
Memory.

84

NOTE: The maximum depth can be reset to 0.0 m
[0 ft] using the optional Suunto Dive Manager PC­Interface.

3. To enter the Freedive History Memory Mode press
the - or + buttons once when the History Memory is
selected. The following Free dive information will be
shown on the display (Fig. 5.10.):

• the maximum depth ever reached

• the longest free dive time ever reached

The freedive history is indicated by a F on the lower
left of the display.

5.3. DATA TRANSFER AND PC­INTERFACE [TR-PC]

The Mosquito can be connected to an IBM compatible
personal computer (PC), using the optional SUUNTO
PC-Interface and the SUUNTO DIVE MANAGER
software. With the PC-Interface dive data from the
Mosquito can be downloaded to a PC. Data can be
added to complete the logbook and paper copies of
your dive log and profi les can easily be printed. The
PC-Interface software can be used for educational and
demonstration purposes, for planning dives, as well
as for keeping complete record of your dive history
with the Mosquito.

The data transfer is carried out using the water contact of the Mosquito. The
following data is transferred to the PC:

• depth profi le of the dive

• dive time

• preceding surface interval time

• dive number

• type of dive (scuba/free)

• Altitude and Personal adjustment settings

• oxygen percentage setting and maximum OLF (in EAN mode)

• tissue calculation data

• temperature at the beginning of the dive, maximum depth and end of the
dive

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

• additional dive information (e.g. SLOW and Mandatory Safety Stop
violations, Diver Attention Symbol, Bookmarks, Surfaced Mark,
Decompression Stop Mark, Ceiling Error Mark)

• dive computer serial number

• personal 30 character information.

It is also possible to manually add comments and other personal information to
the PC based dive data fi les. The SUUNTO PC-Interface package comes complete
with the interface unit, the software on 3.5" disks, and an instruction manual.

85

Fig. 5.11. Data Transfer and
PC-Interface

86

To enter the Data Transfer Mode:

1. In the Memory Mode [MEM], press S three (3)
times to select the Data Transfer Mode The TR-PC
text appears at the bottom of the display to indicate
the selected mode (Fig. 5.11.).

2. Wait two seconds until the Data Transfer Mode
activates automatically.

NOTE: While in the Data Transfer Mode, the water
contact is used only for the data transfer, and when
connecting the contact by submerging it, the Dive
Mode IS NOT automatically activated. Data transfer
stops also the stopwatch.

After you have fi nished the data transfer, Press the
M to exit Data Transfer Mode [TR-PC] and enter the
Memory Mode [MEM]. If no button is operated or
no data is transferred within 5 minutes, the Mosquito
beeps and returns to the timekeeping display
automatically.

Using the PC software, you are able to enter setup
options such as:

• input a personal, 30 character fi eld into the
Mosquito (i.e. your name)

• reset the Dive History’s max depth to zero.

6. CARE AND MAINTENANCE

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

6.1. CARE OF YOUR MOSQUITO

• NEVER try to open the case of the Mosquito.

• Every two years or after 200 dives (whichever comes fi rst) have your
Mosquito serviced by an authorized dealer or distributor. This service
will include a general operational check, replacement of the battery and
a water resistance check and if needed, replacement of the seals, buttons,
or display. The service requires special tools and training. It is advisable
to contact an authorized SUUNTO dealer or distributor for this service.
Do not attempt to do any service that you are not sure about how to do.

• Should moisture appear inside the Mosquito have it checked immediately
by your SUUNTO dealer or distributor.

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

• Check the bars holding the strap and the buckle for fl aws. If necessary,
have them replaced immediately by your SUUNTO dealer or
distributor.

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

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• Protect the unit from shocks, extreme heat or direct sunlight and chemical
attack. The Mosquito cannot withstand the impact of heavy objects like
scuba cylinders, nor chemicals like gasoline, cleaning solvents, aerosol
sprays, adhesive agents, paint, acetone, alcohol etc. Chemical reactions
with such agents will damage seals, case and fi nish.

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

• The Mosquito will display a battery symbol as a warning when the power
gets too low. When this happens, the Mosquito should not be used until
the battery has been replaced (see chapter 3.1.2.).

• Do not fasten the strap of your Mosquito too tightly. You should be able
to insert your fi nger between the strap and your wrist. Use the extension
strap when fastening the Mosquito on your exposure suit.

6.2. MAINTENANCE

If left without care for an extended period, a thin fi lm (often invisible to the eye)
will cover the unit. Much like the buildup on the glass of an aquarium, this fi lm is
the result of organic contaminates found in both salt and fresh water. Suntan oil,
silicone spray and grease will speed up this process. As a result of this buildup,
moisture will be trapped next to the water contact and will not allow your Mosquito
to operate properly.

The water contact can be cleaned with a small brush (e.g. toothbrush).

IMPORTANT: The Mosquito should be soaked, then thoroughly rinsed with
fresh water and then dried with a soft towel after each dive. Make sure that all salt

88

crystals and sand particles have been fl ushed out. Check the display for possible
moisture or water. DO NOT use the Mosquito if you detect any moisture or
water inside.

CAUTION!

• do not use compressed air to blow water off the unit

• do not use solvents or other cleaning fl uids that might cause damage

• do not test or use the Mosquito in pressurized air

6.3. WATER RESISTANCE INSPECTION

Water resistance of the unit must be checked after replacement of the battery,
or after other service operations. The check requires special equipment and
training.

You must frequently check the display for any sign of leaks. If you fi nd moisture
inside your advanced computer watch, 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
Mosquito, if the instructions of this manual are not carefully followed.

In case of a leak immediately bring the Mosquito to an authorized SUUNTO
dealer or distributor.

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6.4. BATTERY REPLACEMENT

NOTE: It is advisable to contact an authorized Suunto dealer for battery

replacement. It is imperative that the change is made in a proper manner to avoid
any leakage of water into the battery compartment or computer.

CAUTION!

• Defects caused by improper battery installation are not covered by the warranty.

CAUTION!

• When the battery is changed all nitrogen and oxygen uptake data is
lost. Therefore, the no-fl ying time shown by the computer should have
reached zero or you must wait for 48 hours or preferably even 100 hours
between dives before you may dive again.

All history and profi le data, as well as the altitude, personal and alarm settings,
will remain in the dive computer memory after the battery change. However, the
clock time and time alarm setting is lost. In the NITROX Mode also the nitrox
settings are reverted back to default settings (21 % O

When working with the battery compartment, cleanliness is extremely important.
Even the smallest dirt particles may cause a leakage when you dive.

BATTERY KIT
The battery kit includes a 3.0 V coin type lithium cell battery and a battery

compartment lid with a lubricated O-ring. When handling the battery do not
make contact with both of the poles at the same time. Do not touch the surfaces
of the battery with your bare fi ngers.

90

, 1.4 bar PO2).

2

BATTERY REPLACEMENT

The battery is located in a separate battery com­partment on the back side of the instrument (Fig. 6.1.).
To change the battery, follow the procedure below:

1. Thoroughly rinse and dry the computer.

2. Open the battery compartment lid by carefully but
fi rmly turning it counterclockwise using a coin or a
screwdriver. When turned the lid should rise from the
compartment. Care should be taken not to damage
any of the parts. Use a large enough coin/screwdriver
in order not to damage the lid.

3. Remove the battery compartment lid with your
fi ngers . Do not use sharp metal objects as they might
damage the O-ring or the sealing surfaces.

4. Carefully remove the battery from underneath the
battery retainer/contact. The battery can be removed
by inserting a screwdriver under the battery and
moving the battery with your fi nger. Be careful not to
damage the electrical contacts or the sealing surface.

Check for any traces of fl ooding or other damage.
In case of a leak or any other damage, bring the
dive computer to an authorized SUUNTO dealer or
distributor for check and repair.

Fig. 6.1.Battery Compartment
Lid

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5. Remove the old O-ring from the battery compartment lid.

6. Check the condition of the old O-ring; a defective O-ring may indicate sealing
or other problems. Dispose the old O-ring and battery compartment lid, even if
they seem to be in good condition.

7. Check that the battery compartment surfaces are clean. Clean with soft cloth
if necessary.

8. Gently insert the new battery under the battery retainer/contact. Check the
polarity of the battery: the “-” mark should point toward the bottom of the
compartment and the “+” mark upwards.

9. Check that the new battery compartment lid and lubricated O-ring are in good
condition. Be very careful not to get any dirt on the o-ring or its sealing surfaces.

10. Orient the lid properly and carefully press the lid onto the battery compartment
with your thumb, while making sure that the O-ring is not at any point protruding
out on the edge. Make sure that the lid is pressed completely down!

11. Turn the battery compartment lid fi rmly but carefully clockwise until it snaps
into its locked position.

12. The dive computer should now active it’s timekeeping mode and show time
18:00 [6:00 PM] and date SA 1.1. Activate the instrument. Check that:

• All display segments work.

• The low battery warning is off.

• The buzzer beeps and backlight works.

• All the settings are correct. Reset if necessary.

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7. TECHNICAL DESCRIPTION

7.1. OPERATING PRINCIPLES

NO-DECOMPRESSION LIMITS

The no-decompression limits displayed by the dive computer for the fi rst dive to
a single depth (see Table 7.1. and 7.2.), are slightly more conservative than those
permitted by the U.S. Navy tables.

TABLE 7.1. NO-DECOMPRESSION TIME LIMITS (MIN) FOR VARIOUS
DEPTHS (M) FOR THE FIRST DIVE OF A SERIES

93

TABLE 7.2. NO-DECOMPRESSION TIME LIMITS (MIN) FOR VARIOUS
DEPTHS [FT] FOR THE FIRST DIVE OF A SERIES

94

ALTITUDE DIVING

The atmospheric pressure is lower at high altitudes than at sea level. After traveling
to a higher altitude, the diver will have additional nitrogen in his body, compared
to the equilibrium situation at the original altitude. This “additional” nitrogen is
released gradually in time and equilibrium is reached. It is recommended that you
adapt to the new altitude by waiting at least three hours before making a dive.

Before high altitude diving, the instrument must be set to the Altitude Adjustment
mode to adjust the calculations for the new altitude. The maximum partial
pressures of nitrogen allowed by the mathematical model of the dive computer
are reduced according to the lower ambient pressure.

As a result, the allowed no-decompression stop limits are considerably reduced.

SURFACE INTERVALS

The dive computer requires a minimum surface interval of 5 minutes between
dives in the Air/EAN mode. If a surface interval is shorter than 5 minutes, the next
dive is treated as a continuation of the previous dive. In Free mode this surface
interval is 2 seconds.

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7.2. REDUCED GRADIENT BUBBLE MODEL,
SUUNTO RGBM

The Suunto Reduced Gradient Bubble Model (RGBM) is a modern algorithm for
predicting both dissolved and free gas in the tissues and blood of divers. It was
developed in a co-operation between Suunto and Bruce R. Wienke BSc, MSc.
PhD. It is based on both laboratory experiments and diving data, including data
from DAN.

It is a signifi cant advance on the classical Haldane models, which do not predict
free gas (microbubbles). It incorporates consistency with real physical laws for gas
kinetics. The advantage of Suunto RGBM is additional safety through its ability to
adapt to a wide variety of situations. Suunto RGBM addresses a number of diving
circumstances outside the range of just dissolved gas models by:

• Monitoring continuous multiday diving

• Computing closely spaced repetitive diving

• Reacting to a dive deeper than the previous dive

• Adapting for rapid ascents which produce high micro-bubble (silent­bubble) build-up.

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SUUNTO RGBM ADAPTIVE DECOMPRESSION

The SUUNTO RGBM algorithm adapts its predictions of both the effects of
micro-bubble build-up and adverse dive profi les in the current dive series. It will
also change these calculations according to the personal adjustment you select.

The pattern and speed of decompression at the surface is adjusted according to
micro-bubble infl uence.

Also on repetitive dives adjustment may be applied to the maximum allowable
nitrogen overpressure in each theoretical tissue group.

Depending on circumstances Suunto RGBM will adapt the decompression
obligations by doing any or all of the following:

• Reducing no-decompression stop dive times

• Adding Mandatory Safety Stops

• Increasing decompression stop times

• Advising an extended surface interval (Diver Attention symbol).

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DIVER ATTENTION SYMBOL – ADVICE TO EXTEND
SURFACE INTERVAL

Some patterns of diving cumulatively add a higher risk of DCI, e.g. dives with
short surface intervals, repetitive dives deeper than earlier ones, multiple ascents,
substantial multiday diving. When this is detected in addition to adapting the
decompression algorithm Suunto RGBM will in some circumstances also advise,
with the Diver Attention Symbol (review chapter 3.2.3.2.) that the diver extend
the surface interval

7.3. OXYGEN EXPOSURE

The oxygen exposure calculations are based on currently accepted exposure time
limit tables and principles. In addition to this the dive computer uses several
methods to conservatively estimate the oxygen exposure. These include for
example:

• the displayed oxygen exposure calculations are rounded to the next higher

whole percentage value

• for recreational scuba diving, the recommended upper limit of 1.4 bar

PO

is used as a default

2

• the CNS% limits up to 1.4 bar are based on 1991 NOAA Diving Manual

limits, but the limits higher than 1.4 bar are signifi cantly shortened

• the OTU monitoring is based on the long-term daily tolerance level and

the recovery rate is reduced.

98