Uwatec Xtender User manual

English
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TABLE OF CONTENTS
XTENDER MANUAL................................................................................2
INTRODUCTION .....................................................................................6
BASIC WATCH USE................................................................................7
BASIC DIVE COMPUTER USE...............................................................9
ADVANCED WATCH FUNCTIONS........................................................15
ADVANCED DIVE COMPUTER FUNCTIONS.......................................17
CHANGE SETTINGS.............................................................................20
TECHNICAL SPECIFICATIONS AND MAINTENANCE ........................27

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XTENDER MANUAL
Thank you for purchasing Xtender, and welcome to SCUBAPRO. Starting today,
you’ll be accompanied on all your dives by a computer featuring advanced
technology for dives in complete safety.
Notes about safety
Like all dive computers, Xtender gives the diver information, but it doesn’t provide
the concepts required to interpret and use this information in a practical way. Dive
computers are no substitute for good sense and a suitable dive training course.
Before using your Xtender dive computer, carefully read and understand the
information provided in this manual.
!CAUTIONS
Scuba diving entails certain risks. Even if you carefully follow the instructions
provided in this manual, potential risks will remain regarding decompression
sickness, oxygen toxicity, and other risks related to diving with Nitrox mixtures or
compressed air. If you are not fully aware of these risks, and if you do not accept
full responsibility for them, do not use Xtender.
Xtender is only programmed for dives using nitrox (max. 99% O2) and compressed
air (21% O2). Do not use Xtender for dives with mixtures of other gases.
Before diving, always check the level of O2set, and compare it with the gas
mix that you will be using. Always keep in mind that entering the wrong mixture
will result in calculations of insufficient decompression time or calculation of an
oxygen toxicity value that is too low. The maximum difference of the mixture
measured must not exceed 1% O2. The wrong gas mixture can be deadly!

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• Always pay attention to the visual and acoustic signals that Xtender provides;
in Nitrox dives never descend beyond the Maximum Operating Depth (MOD)
for the mixture you’re breathing
• Always check the limits of the dive you are preparing for, taking into
consideration the oxygen fraction in the mix and the standard procedures for
recreational diving (decompression sickness, oxygen toxicity)
• As all your courses will tell you, avoid diving to depths deeper than 40 meters
(130 feet); the danger of nitrogen narcosis must be kept in mind, and Xtender
does not warn you about this risk
• In all dives with Xtender, make a safety stop of at least three minutes at
5 meters (16 feet); Xtender features a safety stop timer designed to make this
procedure easier
• All divers who use a computer to monitor their decompression status must
use their own individual computer, and always wear it during all dives taken
close together in a short period of time
• If Xtender stops working at any point during the dive, the dive must be
terminated and you should ascend slowly, executing your 3-5 minute safety
stop at the depth of 5 meters (16 feet)
• Always comply with the ascent rate indicated by Xtender and make all the
required decompression stops. If the computer malfunctions, do not exceed
the maximum speed of 10 meters (32 feet) per minute as you ascend
• During any dive, pairs or groups of divers must follow the indications given by
the most conservative computer
• Never dive alone: Xtender cannot replace a dive buddy!
• Avoid ascending and descending repeatedly (yo-yo dives)
• Avoid an excessive work load at depth
• In cold water, plan shorter dives
• After decompression, or at the end of a no-decompression dive, ascend as
slowly as possible through the final few meters
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• Before using Xtender, you must be familiar with the signs and symptoms
of decompression sickness: if after a dive any of these signs or symptoms
appear, IMMEDIATELY seek specialized medical attention. In fact, the faster
a diver begins treatment after symptoms appear, the more effective that
treatment will be
• Do not dive with Nitrox before earning a specific certification from an
accredited teaching institution.
Nitrox and repetitive dives
• For subsequent dives, wait until the CNS O2% value drops below 40%
• Nitrox dives: make sure you have sufficient surface time (as for dives using
air). Plan for a minimum of two hours of surface time. Even oxygen requires a
certain period before it is expelled from the body
• Always choose the most suitable mixture for the dive you have planned
• Refrain from diving at least one day each week
• Repetitive dives with different computers: wait at least 48 hours before diving
with a computer that you have not used during your previous dives.
Dives at altitude
• Do not dive at altitudes of more than 4,000 meters (13,000 feet)
• After a dive, Xtender indicates the altitude that must not be exceeded using
flashing segments.
Flying after a dive
• After the dive, wait at least 24 hours before traveling by air.
Xtender is personal protective equipment (PPE) that meets the essential
safety requirements called for by European Union Directive 89/686/EEC.
RINA SpA (notified body #0474) has certified its compliance with standard
EN 13319:2000.
• EN 13319:2000 “Depth gauges and combined depth and time”.

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!WARNING
All information regarding decompression requirements shown by the
instrumentation is explicitly excluded from the realm of validity of these
standards.

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INTRODUCTION
We know that you can’t wait to try out your Xtender in the water, so we have
divided this manual into two sections: the first explains the basic functions and
operations needed to use the computer right away, and it is essential that you
read it before taking your computer on a dive. The second describes supplemental
operations and technical specifications, and you can consult this section as
needed (although we highly recommend that you read it before using Xtender).
N2 O2
Arrangement of the display and buttons
The Xtender case has four buttons and one wet contact. The description of button
operations will be identified with the word engraved on the Xtender ferrule:
[A] “mode” is used to change the usage mode
[B] “lock” activates and deactivates the option to change settings
[C] “select” allows you to move from one value to the next, and to increase
the value you are changing
[B] lock
[E] wet
contact
[A] mode
[C] select
[D] light/set

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[D] “light/set” activates the display backlight, and during adjustments it
decreases the value you are changing
[E] wet The metallic contact on the left side of the computer is there to
contact tell Xtender that you have entered the water, and has no specific
function on the surface except to interface the dive computer
with a PC.
BASIC WATCH USE
When using Xtender on the surface, it will be in watch mode; it returns to this
mode after each adjustment operation and 5 minutes after the end of each dive
(Fig. 1).
day of the
week
alarm clock
icon
time
month and day
hourly signal
icon
Figure 1
Pressing “select” will display the second time zone, desaturation time, and the
surface time.

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Adjusting the date and time
Press the “lock” button and choose the value you want to change with the
“select” button; the sequence is: seconds > minutes > hour > year > month >
days > hour format > seconds >... The value you are changing will flash, and you
can increase it one unit at a time by pressing the “light/set” button. Press and
hold the button to scroll through the values quickly. When adjusting the seconds,
if you press “light/set” when the value is between 30 and 59, one minute will be
added; the same is true for day, month, and year.
When adjusting the hour, moving from 59 minutes to 00 does not change the
hour value, just as moving from hour 23 to hour 0 does not move you to the
next day.
You can also choose whether you want to display the time in AM/PM or 24 hour
format by pressing the “light/set” button when the hour number and minute
number are flashing. The AM/PM format is indicated by the letter “A” or “P”
shown to the left of the time value, respectively from 12:00AM and 11:59AM and
from 12:00PM and 11:59PM.
After making your changes, press “lock” again to return to watch mode, or
simply wait 2-3 minutes.
Setting the alarm clock
The alarm clock function lets you set a daily alarm, or activate or deactivate an
hourly signal. Access alarm clock mode with the “mode” button; the letters “AL”
will replace the indication of the date. Then, press the “lock” key, which will allow
you to set the time. Once you have made your changes, press “lock” again
to return to alarm clock mode. Now choose whether you want to enable the
alarm, the hourly signal, or both, using the “select” button. Depending on your
selections, the alarm clock icon, hourly signal icon, both, or neither will appear
above the time.

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Backlighting
The “light/set” button enables backlighting; the “select” button activates lighting
and also shows the secondary display, with information about the mode the
computer is in at that time. In order to limit battery consumption, backlighting is
automatically disabled after three seconds.
BASIC DIVE COMPUTER USE
When Xtender is used as a dive computer, it shows all the information needed for
no-decompression and decompression dives, either with air or Nitrox mixtures.
Functions during the dive
As soon as Xtender detects contact with the water, it turns on and begins to
show the depth, updating the value on the screen once per second. Once the
depth exceeds 1.5 meters (5 feet), it also begins counting the dive time elapsed.
Total dive time is measured up to a maximum of 599 minutes, and the computer
continues to count until ten minutes after surfacing, at which point the dive is
considered over and its data are stored in the logbook.
During the dive Xtender gives a numeric readout of the current and maximum
depth, the dive time, time left for a no-decompression dive or the decompression
stop required, the ascent speed, the oxygen partial pressure, and the water
temperature. Further, two bar graphs indicate the nitrogen saturation level and
the accumulation of oxygen in the central nervous system (CNS O2).

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Information shown on the display
The display provides two different sets of information, depending on whether the
dive is within no-decompression limits (Fig. 2) or is a decompression dive (Fig. 3).
nitrox icon
Figure 2
Figure 3

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Regardless of the type of dive, you can use the buttons to access other information
that is not shown on the main screen in dive mode. Pressing the “mode” button
will display: The current time, the oxygen percentage set (from 22 to 99 percent,
or “Air”), and the personal safety level selected.
The “select” button will display the maximum depth reached up to that point, the
water temperature, and the dive time.
On the left side of the display, a bar graph provides a visual indication of the
nitrogen saturation level. The bar is divided into nine segments; if all of them are
activated (that is, the bar reaches the top of the display), the dive becomes a
decompression dive (Fig. 4).
nitrogen
saturation
level
Figure 4
On the right side of the display there is another bar, similar to the one for nitrogen, but
divided into eight segments, representing the level of oxygen toxicity on the Central
Nervous System. During dives with air to depths of less than 40 meters, the CNS
value will increase slowly, but on a Nitrox dive it is important to monitor this value
closely; this will be described in detail in the corresponding section.

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Repetitive dives
A repetitive dive means taking a second dive before a sufficient amount of time
has elapsed to allow you to completely desaturate the nitrogen accumulated from
your previous dive. In these cases, Xtender shows the level of nitrogen using the
bar graph, and the desaturation time required (Fig. 5).
Figure 5
If you dive during this period, the no-decompression times available will be
shorter, because Xtender takes into account the nitrogen already present in your
tissues.
The dive planner allows you to monitor the no-decompression times allowed by
the computer. To view the desaturation time and surface time, press the “select”
button.
Nitrox dives
When you dive with Nitrox mixtures, it is necessary that you enter into Xtender the
oxygen fraction contained in the gas you will be using on the dive. Is crucial that
the oxygen fraction corresponds to the mix in your tank, because this information
is the basis for the decompression calculations as well as for oxygen toxicity.

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In order to set the oxygen fraction, access planning mode by pressing the “mode”
button and then the “lock” button. The first value you will see is FO2, and you can
change it using the “light/set” button. Each time you press the button the oxygen
fraction increases by 1%.
The initial value is 21% (air), and you can set values up to (99%), and then the
cycles goes back to 21. To make it easier to set this value, if you hold down the
“light/set” button, the values scroll by faster, pausing briefly at 32% and 99%.
If you do not set any value, Xtender shows “- -” in the display area reserved for
FO2, but if a value is entered, Xtender switches to Nitrox mode and the “NX”
icon activates.
Figure 6
When Xtender is in Nitrox mode and at a depth of more than 1.5 meters (5 feet), it
also indicates the oxygen partial pressure right above the “NX” icon.

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Alarm signals
In situations that endanger the diver, Xtender uses different acoustic signals to
warn about the risk:
• Excessive ascent speed: acoustic alarm every 3 seconds
An excessive ascent speed will be signaled by the indication of the current
depth flashing for six seconds and the word SLOW. Along with each signal,
an acoustic alarm is emitted lasting 6 seconds (Fig. 7)
• Begin decompression phase: acoustic alarm for 3 seconds, repeated twice
• Decompression omitted: acoustic alarm for 3 seconds, repeated twice
• Operating limits exceeded: acoustic alarm for 3 seconds, repeated twice
• O2level alarm: acoustic alarm for 3 seconds, repeated twice
• PO2alarm: acoustic alarm for 3 seconds, repeated twice
• FO2setting alarm: acoustic alarm for 3 seconds, repeated twice
• Saturation level alarm: acoustic alarm for 3 seconds, repeated twice
• Setting not allowed alarm: acoustic alarm for 3 seconds, repeated twice
• Dive mode not allowed: acoustic alarm as long as the wet contact detects
the presence of water.
Figure 7

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Note:
• The acoustic alarms can not be deactivated using the buttons
• If two alarms are activated simultaneously, the first is canceled and
the second begins
• The alarm clock sound can be deactivated by pressing one of the
buttons. You can deactivate the alarm clock alert during the first
20 seconds. When you deactivate the alarm, the icon stops flashing
but stays on
• The alarms activated in Dive Mode are deactivated when the
computer detects a depth of less than 1.4 meters (4.5 feet) and the
E button no longer detects contact with the water
• The alarms indicating that a certain setting or given mode cannot be
accessed are interrupted when the wet contact button detects water.
ADVANCED WATCH FUNCTIONS
Automatic return
When Xtender is in Alarm Clock, Second Time Zone, Planner, or Logbook Mode
(or a mode other than Watch Mode) and the mode is changed by pressing the
“mode” button after any of the other buttons have been used, the computer
automatically returns to Watch Mode. In all modes except for Dive Mode or Time
Set Mode, the computer automatically returns to Watch Mode if no button is
pressed for 2-3 minutes (or 14-15 minutes when in PC data Transfer Mode). In
Dive Mode, the computer returns to Watch Mode 2-3 minutes after the display
has been automatically updated.
Second Time Zone
Xtender keeps track of the current time in two time zones, which is very useful for
divers who travel a lot. The second time zone can differ ±23 hours and 30 minutes

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from the main time zone, and is displayed by pressing the “select” button; the
display will also show the “dual” indication.
To set the second time zone, access the corresponding mode by pressing the
“mode” button until the second time zone appears in the upper section of the
display. Press “lock” and move the time forward with the “select” button or
backward with the “light/set” button. If you hold down either button the time
will scroll faster. To change the date for the second time zone, move through a
complete 24-hour cycle; it is not however possible to specify more than one day
of difference between the local time and the second time zone.
Note: If the dive ended less than 10 minutes earlier, it is not possible to
display or set the second time zone, and pressing the “select” button
will emit an acoustic alarm.
Daily alarm / hourly signal
The alarm clock function activates an acoustic alarm each day at the set time; the
hourly signal emits a brief signal at the beginning of each hour. In order to access
the time set for the alarm clock, use the “lock” button and then press “select”
to move from hours to minutes (Minutes > Hours > Minutes >... the cycle starts
over). Both are adjusted using the “select” button. Hold the button down to scroll
quickly through the values. When you are done setting the time, the alarm clock
mode is activated automatically. The Alarm clock and hourly signal are activated/
deactivated using the “select” button when Xtender is in alarm clock set mode.

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ADVANCED DIVE COMPUTER FUNCTIONS
Viewing the nitrogen saturation level
During the dive, on the left side of the display there is a bar graph composed
of nine LCD segments, corresponding to the colored scale on the side of the
display itself. As the saturation level calculated by the algorithm increases, more
segments are activated. When all the segments are active, the dive requires
decompression.
Sometimes on the surface, the bar graph may be activated following a change in
altitude (decrease in atmospheric pressure). If the graph reaches nine segments,
dive mode will not be accessible, and an alarm will sound if the computer comes
into contact with the water.
Setting the additional safety level
The Xtender algorithm allows you to calculate decompression more conservatively,
for example in the case of very demanding dives or difficult conditions. To activate
this function, access planning mode (“plan”), then press “lock”, “select”, and
then activate or deactivate the additional safety factor by setting the SF (Safety
Factor) value to 1 or 0. The preselected setting is 0 (deactivated).
Display of O2saturation – Oxygen toxicity alarm
The bar graph on the right side of the display shows the oxygen toxicity level
on the Central Nervous System using eight LCD segments that are activated in
proportion to the diver’s exposure to an elevated partial pressure of oxygen.
When the seventh segment is reached, the entire graph flashes for 15 seconds,
and two 3-second alarms will sound. If the eighth segment is reached, the same
acoustic alarm will sound and the graphic continues to flash, and the alarm is
recorded in the logbook. These alarms are also activated on the surface if the
saturation is at level 7 or 8 and the wet contact detects the beginning of a dive
(Fig. 8).

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oxygen
toxicity
level
Figure 8
Indication of oxygen partial pressure
When you are below 1.5 meters (5 feet) and the oxygen fraction (FO2) of the
mixture is set to a value equal or greater to 22%, a ppO2indicator is displayed.
Safety block
When the operating limits of Xtender are exceeded or a decompression stop is
skipped, the display will block: all segments of the display will begin flashing, and
you will not be able to access dive planning, settings, or dive modes.
The block ends after 48 hours, or after you complete the reset procedure
(simultaneously hold down the “select” and “light/set” button for at least
15 seconds while the computer is in watch mode).

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Altitude measurement
Xtender detects the altitude every 10 minutes and indicates it with the mountain
icons (Fig. 9). When the computer is in dive mode or data transfer mode, this
measurement is disabled. The altitude icon is not visible in the following modes:
Watch Settings, Set Alarm Clock, Set Second Time Zone, Clear History, Dive
Profile, and when the History is displayed in the Logbook area.
Altitude level Altitude Indication on the display
0 Up to 1000 m None
1700-1800 m Level 1 segment lit
2 1500-2600 m Level 2 segment lit
3 2300-6000 m Level 3 segment lit
Error over 6000 m Level 3 segment flashing
<Indication of altitude levels 1,2,3> <Indication of altitude level error>
Figure 9

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Surface time
Beginning 10 minutes after the end of the dive, Xtender shows the surface time,
which is counted for 48 hours and can be displayed by pressing “select”. After
48 hours, it will simply show “- -:- -” (Fig. 10).
mode
indicator
Figure 10
CHANGE SETTINGS
Select unit of measure
The pre-selected units of measure are those of the decimal metric system (meters
and degrees Celsius); you can however select Imperial units (feet and degrees
Fahrenheit) for depth and temperature. To choose the desired units of measure,
hold down the “lock” button for approximately 15 seconds.
Dive Planner
Xtender has a dive planner that shows the no-decompression limits between 9
and 48 meters. The planner is activated by pressing the “mode” button and is
indicated by the “plan” button in the lower portion of the display; the “select”