Crest Audio CR-4 User manual

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CREST
CR-4 Dive Computer
Applicable to SW version C01-4C
USER GUIDE

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CREST CR-4 Dive Computer User Guide
CREST 1
CR-4 Dive Computer 1
1. Screen and Functions 3
1.1 Button function 3
1.2 Menu 4
1.3 Watch Mode and Dive History & System Information 7
1.3.1 Watch Mode 7
1.3.2 Dive History & System Information 8
1.3.3 Watch Mode Settings 10
1.4 Scuba Mode and Settings 13
1.4.1 Scuba Mode 13
1.4.2 Scuba Mode Settings 18
1.5 Gauge Mode 25
1.6 Freediving Mode and Settings 26
1.6.1 Freediving Mode 26
1.6.2 Freediving Mode Settings 28
1.7 Log Mode 32
1.8 Settings Mode 33
1.9 Synchronization Mode 38
CREST Contact info 39

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1. Screen and Functions
1.1 Button function
Name ：Power
Button
Locate：Left Top
Func ：Power
Switch / Exit
Name ：Up Button
Locate：Right Top
Func ：Move Pointer
Up / Acees more
Settings
Name ：Mode /
Select Button
Locate：Right Middle
Func ：Menu / Enter
Value
Name ：Down Button
Locate：Right Down
Func ：Move Pointer
Down / Access Dive
History & System
Information (Under
Watch Mode)

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1.2 Menu
1.2 Menu
Description: Watch Mode
To Access: Default mode when your turn
on.
To Exit: Press Power Button once.
Description: Scuba Mode
To Access: Under Menu, press Mode
Button to select Scuba Mode.
To Exit: Press Power Button once.
Description: Gauge Mode
To Access: Under Menu, press Mode
Button to select Gauge Mode.
To Exit: Press Power Button once.

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1.2 Menu
Description: Freediving Mode
To Access: Under Menu, press Mode
Button to select Freediving Mode.
To Exit: Press Power Button once.
Description: Dive Logs
To Access: Under Menu, press Mode
Button to select Dive Logs. Use UP Button
/ DOWN Button to access the different
dives logs stored in the memory. They are
stored in order by date.
To Exit: Press Power Button once.
Description: Settings
To Access: Press Mode Button to go to
system settings. Use UP Button / DOWN
Button to see the different setting options.
To Exit: Press Power Button once.

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1.2 Menu
Description: Synchronization Mode
(SYNC Mode)
To Access: Press Mode Button to go to
Synchronization Mode (SYNC Mode).
This function will activate the wireless sync
transmission. The watch will broadcast
signals as long as it is turned on and the
screen icon shows a blinking dotted line.
To Exit: Press Power Button once.

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1.3 Watch Mode and Dive History & System
Information
1.3.1 Watch Mode
Description: Default mode when your turn
on. Displays day of the week, current time
and calendar date.
To Access: Under Menu, press Mode
Button to select Watch mode or press
Power Button to go back to default.
Events during this function:
1. When dive computer is not being used
or the G-Sensor does not sense
movement after preset time, Auto
Power Off functions will apply and it will
go to Standby Status (blank screen). To
change the preset time, please check
page 33 for Power Auto Off.
2. When the computer is not used for a
longer period of time (24 hours.) it will
go to Sleep Status for better battery
management.
3. Under Standby Status, you may wake
up dive computer by twisting it over 45
degrees to activate the G-Sensor, or
press any button.
4. Under Sleep Status, you can only turn
on dive computer by pressing the
power button. All the settings and data
will remain in memory.
WARNING: Always check your dive
computer status before your dive. If
dive computer is under Sleep Status,
it will NOT start automatically when
you enter water.

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1.3.2 Dive History & System Information
Description: Last Dive
Displays latest dive log:
Calendar date, Time;
No FLY recommendation time
countdown;
No DIVE recommendation time
countdown;
Surface Interval (SI) time counting;
(continues until diver starts a new dive).
To Access: Under Watch Mode, press
DOWN Button once.
Description: SCUBA HISTORY
Displays dives under Scuba Mode:
Dive counts
Accumulated dive time
Maximum Operating Depth (MOD)
To Access: Under Watch Mode, press
DOWN Button twice.
Description: FREEDIVING HISTORY
Displays dives under Freediving Mode:
Dive counts
Maximum Operating Depth (MOD)
Length of Time (LOT)
To Access: Under Watch Mode, press
DOWN Button three times.

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1.3.2 Dive History & System Information
Description: VERSION
Displays system information of dive
computer.
HW: Hardware version of dive computer
SW: Software version of dive computer
SN: Serial Number of dive computer
To Access: Under Watch Mode, press
DOWN Button four times.
To Exit: Under Watch Mode, press DOWN
Button five times.

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1.3.3 Watch Mode Settings
Description: Date Settings
To Access: Under Watch Mode, press the
UP Button once, and press UP Button /
DOWN Button to locate the cursor and
then press MODE Button once to select
the desired settings. The values at the
bottom of the screen will blink.
DATE Settings: Changes the values of 3
groups of digits corresponding to Month,
Day and Year using UP Button / DOWN
Button to select and accept the selection
with MODE Button.
Description: Date Format Settings
To Access: Under Watch Mode, press the
UP Button once, and press UP Button /
DOWN Button to locate the cursor and
then press MODE Button once to select
the desired settings. The values at the
bottom of the screen will blink.
DATE FORMAT Settings: Changes the
order in which the Day, Month and Year
are displayed on dive computer to
accommodate the region of the world you
live in. Use UP Button / DOWN Button to
select and accept the selection with MODE
Button.
Description: Time Settings
To Access: Under Watch Mode, press the
UP Button once, and press UP Button /
DOWN Button to locate the cursor and
then press MODE Button once to select
the desired settings. The values at the
bottom of the screen will blink.
TIME Settings: Changes the values for
Hours and Minutes so the correct time can
be displayed on dive computer. Use UP
Button / DOWN Button to select and
accept the selection with MODE Button.
Note: Please be aware that the watch
will not self-adjust for daylight savings
time.

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1.3.3 Watch Mode Settings
Description: UTC Settings (Coordinated
Universal Time Settings)
To Access: Under Watch Mode, press the
UP Button once, and press UP Button /
DOWN Button to locate the cursor and
then press MODE Button once to select
the desired settings. The values at the
bottom of the screen will blink.
UTC Settings: Change the values
corresponding with your particular time
zone with the UP Button / DOWN Button
and accept the selection with MODE
Button.
Note: Make sure you edit your
CORRECT UTC + or - hours for your
particular time zone first then go to
settings again and, if needed, edit your
TIME settings. If you do it backwards,
time will not coincide & information will
be inaccurate.
Description: Time Format Settings
To Access: Under Watch Mode, press the
UP Button once, and press UP Button /
DOWN Button to locate the cursor and
then press MODE Button once to select
the desired settings. The values at the
bottom of the screen will blink.
Time Format Settings:
12H / 24H
Use UP Button / DOWN Button to select
and accept the selection with MODE
Button.

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1.3.3 Watch Mode Settings
Description: Auto Active Mode at depth:
Scuba Diving, Freediving, or Gauge
(bottom timer).
To Access: Under Watch Mode, press the
UP Button once, and press UP Button /
DOWN Button to locate the cursor and
then press MODE Button once to select
the desired settings. The values at the
bottom of the screen will blink.
AUTO MODE will be the automatic
default option dive computer will
access immediately after it senses a
depth of at least 1.5m (4.9 ft.). For Log
Start Depth please go to Log Start Settings
on page 23.
Description: Language Settings
To Access: Under Watch Mode, press the
UP Button once, and press UP Button /
DOWN Button to locate the cursor and
then press MODE Button once to select
the desired settings. The values at the
bottom of the screen will blink.
Default option is English.
Note: Supports English/Traditional
Chinese after SW version of C01-4A.
Description: Exit
To Access: Under Watch Mode, press the
UP Button once, and press UP Button /
DOWN Button to locate the cursor at EXIT
and then press MODE Button to select; or
press Power Button once.

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1.4 Scuba Mode and Settings
1.4.1 Scuba Mode
Scuba Mode:
To Access: Under Menu, press t UP
Button / DOWN Button to locate the cursor
and then press MODE Button once to
select Scuba Mode.
To Exit: Press Power Button once.
Description: Scuba Preview Mode
Image on Top: Normal Display
Image at bottom: Large Display
OC: Open-Circuit Scuba
: Battery Status
000.0 m: Current depth.
CF: Conservative. 3 levels to select:
CF-1(Conservative), CF-2(Normal), and
CF-3(Aggressive). Default: CF-2.
TIME: Dive Time.
PPO2: Current setup of PPO2 (partial
pressure of oxygen). Setup range: from
1.2 to 1.6. Default: 1.4.
MOD: Maximum Operating Depth
suggestions.
O2%：Oxygen percentage value. Default:
21%.

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1.4.1 Scuba Mode
Description: Scuba Under Water Mode
Image on Top: Normal Display
Image at bottom: Large Display
18.6m: Current Depth
NDL: The Non-Decompression Limit time
in minutes.
TIME: Dive time.
：Ascent speed in meter/minute. If
reaches 10meter/minutes, there will be
alarm warning.
：Descent speed in meter/minute.
NO arrow icon: Diver is stationary.
09:35: Current time.
TEMP：Water temperature.
Description: Scuba Under Water Mode –
When the NDL has not been exceeded
Image on Top: Normal Display
Image at bottom: Large Display
005.6m: Current Depth
STOP: When diver ascent to 5m (16.4 ft),
diver computer will start safety stop
countdown of 5 minutes.
TIME: Dive time.
：Ascent speed in meter/minute. If
reaches 10meter/minutes, there will be
alarm warning.
：Descent speed in meter/minute.
NO arrow icon: Diver is stationary.
CEILING: The depth at which you
should ascend to & remain.
TEMP：Water temperature.

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1.4.1 Scuba Mode
Description: Scuba Under Water Mode –
When the NDL has not been exceeded
Image on Top: Normal Display
Image at bottom: Large Display
CLEAR: When you finish the safety stop at
the CEILING depth, dive computer will
show the word CLEAR indicating that it is
OK to perform a slow ascent to the
surface.
TIME: Dive time.
：Ascent speed in meter/minute. If
reaches 10meter/minutes, there will be
alarm warning.
：Descent speed in meter/minute.
NO arrow icon: Diver is stationary.
09:35: Current time.
TEMP：Water temperature.
Description: Scuba Under Water Mode –
When the NDL has been exceeded
Image on Top: Normal Display
Image at bottom: Large Display
NDL: When exceed the NDL time, the first
3 minutes will be shown in: mins: seconds
CEILING: The depth at which you should
ascend to & remain, when you are required
to perform decompression stops.
WARNING: When the NDL is exceed
divers should not perform a direct
ascent to the surface. Decompression
stops will have to be performed instead.
CEILING indicates the depth at which
the diver must go to AND stop & wait
for the timer countdown to end. The
NDL will adjust automatically. Only after
the screen CLEAR shows at the left of
the screen, the diver can now ascend to
the surface.

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1.4.1 Scuba Mode
Description: Scuba Under Water Mode –
When the NDL has been exceeded
Image on Top: Normal Display
Image at bottom: Large Display
NDL: When exceed the NDL time, the first
3 minutes will be shown in: mins: seconds.
When exceed time passes over 3 minutes,
the NDL time is shown in minutes.
CEILING: The depth at which you should
ascend to & remain, when you are required
to perform decompression stops.
WARNING: When the NDL is exceed
divers should not perform a direct
ascent to the surface. Decompression
stops will have to be performed instead.
CEILING indicates the depth at which
the diver must go to AND stop & wait
for the timer countdown to end. The
NDL will adjust automatically. Only after
the screen CLEAR shows at the left of
the screen, the diver can now ascend to
the surface.
Description: Scuba Under Water Mode -
When exceed the NDL and ascent to
ceiling depth.
Image on Top: Normal Display
Image at bottom: Large Display
STOP: After reaching CEILING depth, the
remaining amount of time indicated on the
screen will be displayed as countdown
timer. Please remain at the ceiling depth
the entire duration indicated by the
countdown timer if you have enough air
and no other potential risks are evident.

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1.4.1 Scuba Mode
Description: Scuba Under Water Mode -
When exceeding the NDL, and the Deco
stop at CEILING has ended.
Image on Top: Normal Display
Image at bottom: Large Display
CLEAR：When you finish the deco stop at
CEILING depth, dive computer shows
CLEAR means it is OK to perform a slow
ascent to surface.
WARNING:
The decompression options provided by
the dive computer & presented in this
manual should only be used as emergency
procedures when a NDS limit has been
accidentally surpassed.
Decompression Diving Warning For
Recreational Divers:
It is important to remember that
decompression stops are driven by both
depth and NDL violations. It is possible to
see more than one deco stop and
potentially several CEILING indications at
different times depending how severe the
depth and time violation has been.
Decompression diving is not an activity
that should be performed by recreational
divers as a standard practice.
Decompression diving requires extensive
training, deep knowledge of diving physics
and diving physiology and several pieces
of extra gear and sufficient gas supply to
safely perform the required stops. We
strongly discourage recreational divers
from performing decompression diving.

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1.4.2 Scuba Mode Settings
Description: Scuba Preview Mode
Image on Top: Normal Display
Image at bottom: Large Display
To Access: Under Menu, press UP Button
/ DOWN Button to locate the cursor and
then press MODE Button once to select
Scuba Mode.
For more information, please check page
13 for Scuba Preview Mode.
Description: Nitrox Setting
To Access: Under Scuba Preview Mode,
press UP Button Or from SETTINGS,
press UP Button / DOWN Button to locate
the cursor at Nitrox and then press MODE
Button to select.
The Oxygen percentage value at the
bottom of the screen will start blinking.
Switch the option with UP Button / DOWN
Button, once the desired Nitrox option
appears, select it by pressing MODE
button once to accept the value. Dive
computer will recalculate the MOD and will
be presenting NDL values corresponding
with the EANx and PO2 values previously
set.
You may set the EANx range from 21% to
56%. For air diving calculations please
make sure dive computer is set at 21%.
WARNING:
Please make sure you have measured the
EANx gas of the cylinder you are about to
dive with and correctly input that value in
your computer. Before using NITROX, you

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1.4.2 Scuba Mode Settings
MUST have received proper training and a
certification that qualifies you to use such
gas. Diving with Oxygen enriched mixes
carries an additional layer of risk.
Description: PPO2 Setting
To Access: Under Scuba Preview Mode,
press UP Button Or from SETTINGS,
press UP Button / DOWN Button to locate
the cursor at PPO2 and then press MODE
Button to select.
The PPO2 value at the bottom of the
screen will start blinking. Switch the option
with the UP Button / DOWN Button, once
the desired PPO2 option appears, select it
by pressing MODE button once to accept
the value. Dive computer will recalculate
the MOD and will present the NDL values
corresponding with the EANx and PPO2
values previously set.
You may set the PPO2 range from 1.2 to
1.4. For air diving calculations please
make sure the computer is set at 1.4.
WARNING:
Please make sure you have measured
the EANx gas of the cylinder you are
about to dive with and correctly input
that value in your computer. Before
using NITROX, you MUST have received
proper training and a certification that
qualifies you to use such gas. Diving
with Oxygen enriched mixes carries an
additional layer of risk. PPO2 values
will affect the MOD of your dive. High
PPO2 values in combination with high
EANx concentrations will increase the
risk of oxygen toxicity.

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1.4.2 Scuba Mode Settings
Description: Conservative Factor
Settings
To Access: Under Scuba Preview Mode,
press UP Button Or from SETTINGS,
press UP Button / DOWN Button to locate
the cursor at CF and then press MODE
Button to select.
The CF value at the bottom of the screen
will start blinking. Switch the option with
the UP Button / DOWN Button once the
desired CF option appears select it by
pressing the MODE button once to accept
the value. The computer will recalculate
and present the NDL values corresponding
with the pre-set conservative value you
enter.
Options:
There are 3 CF levels:
CF1 (Conservative), CF2 (Normal) and
CF3 (Aggressive).
WARNING:
Please make sure you fully understand
that changing this setting will affect
algorithm calculations and the related
risks.
Description: Depth Alarm –ON/OFF
To Access: Under Scuba Preview Mode,
press UP Button Or from SETTINGS,
press UP Button / DOWN Button to locate
the cursor at SDPT-ALM and then press
MODE Button to select.
One of the two options will be blinking at
the bottom. Press UP Button / DOWN
Button to select and press MODE Button
once to accept your selection.
If you set the SDPTH-ALM on, when you
reach the preset depth, the alarm will
activate.
S = Scuba
DPTH = Depth
ALM = Alarm