Support & Downloads



For full instructions with pictures explaining the best way to remove and replace the O-ring, please click HERE

We are sorry that you are having a problem with your dive computer that can't be resolved with our FAQ’s.  If your dive computer needs some kind of repair, simply email us at to initiate the process.

Please include your name, address and phone number, description of your problem, unit model, S/N and Firmware Version.  We’ll get you an RMA number and instructions on how to send your computer in for repair. Please do not return your computer to us or any of our service centers without an RMA number.

To find your S/N and firmware, turn on your computer (unless it won’t turn on) and from the main screen press the right side button 8-10 times until you see the S/N displayed (lower left) and Firmware (lower right) of the screen.

The standard transmitters all use the same transmit interval, so there is a small chance they may interfere with one another when using two or more at the same time with one Perdix AI.  One way to resolve this is to shut off the air to one transmitter (purge pressure to 0) for at least 2 minutes, then restore the pressure.  This may be done underwater, of course choosing to shut off the source not being used for breathing at the time.  An alternate solution is also available by using a different transmit interval device for the second transmitter.  Compatible transmitters (FCC ID: MH8A) with different transmit intervals are available – look for colour coded units (green or yellow are both different from the standard units). Yellow transmitters are also available through Shearwater. Standard units are identified by the black or grey case.

While almost any kind of AA battery will work with your Shearwater Perdix, 1.5V lithium batteries like the Energizer Ultimate Lithium work best. This battery type performs well in a wide temperature range and is much less likely to leak and cause damage to your dive computer. 

Read more here:

Depth is not measured directly. Dive computers measure pressure, and convert this to depth based on an assumed density of water.

Water density varies by type. The weight of salts dissolved in saltwater make it heavier than freshwater. If two dive computers are using different densities of water, then their displayed depths will differ.

The water type can be adjusted on the Perdix. In the System Setup->Mode Setup menu, the Salinity setting can be set to Fresh, EN13319, or Salt.

The EN13319 (European CE standard for dive computers) value is between fresh and salt and is the Perdix default value. The EN13319 value corresponds to a 10m increase in depth for pressure increase of 1 bar.

The density value used for each setting is:

  • Fresh Water = 1000kg/m³
  • EN13319 = 1020 kg/m³
  • Salt Water = 1030 kg/m³

In Gauge Mode the Perdix does not know what gas you are breathing and therefore cannot track the inert gas tissue loading.

  • The Shearwater Perdix should be stored in a clean, cool and dry environment.
  • Do not allow salt deposits to build up on your dive computer. Wash your computer with freshwater to remove salt and other contaminants.
  • Do not use detergents or other cleaning chemicals as they may damage the Perdix dive computer.
  • Allow to dry naturally before storing.
  • Do not wash with high pressure water as it may damage the depth sensor.
  • Store the Shearwater Perdix out of direct sunlight in a cool, dry and dust free environment. Avoid exposure to direct ultra-violet radiation and radiant heat.
  • Do not store batteries in the Perdix for long periods (several months). Batteries can and do leak, so don’t risk your expensive computer on a simple task like removing batteries. Dead batteries are at a higher risk of leaking.

Shearwater has a 2 year warranty on all products. The warranty lives with the unit, not with the original purchaser. This means that whether you buy your unit from our dealer network or second-hand the warranty will still be effective. Once the warranty period has passed computers should be serviced every 2 years at your nearest service center.

It is unnecessary to register your unit upon purchase. Every Shearwater unit is tracked with a unique serial number.

Yes, to unlock dive log recovery, go to “Dive Log->Edit Log Number” and set this to “9997”.


Now the “Clear Logs” menu option will be changed to “Restore Logs”. This will restore all deleted logs. To restore individually, go to the “Dive Log->Display Logs” page. Deleted logs will be grayed-out. Select the dive to restore, then press the right button until the “Edit Dive” menu comes up. This will have a restore option.


Remember to go back to “Edit Log Number” and set it back to its previous value. The next dive # will be the number entered here plus one (e.g. If 2 is entered, the next dive will be dive #3).

Yes, all settings and dive logs are saved in permanent (non-volatile) memory and restored after the battery is changed.

To reset the settings to defaults, use the “System Setup->Reset to Defaults” menu. You can choose to reset the settings, the deco tissues, or both.

When the battery is removed the clock stops running. Upon installation of the battery, the clock is loaded to the last saved value (saved every 16 seconds when on, and every 5 minutes when off).

The Perdix uses a highly accurate quartz crystal for time keeping. A maximum error of about 1 minute per month can be expected. Larger errors are likely due to the clock being stopped while the battery is removed during a battery change.

battery changed clock

After a battery change a screen is displayed that allows quick access to correcting the time. The time can also be corrected in the System Setup menu.

The Perdix will automatically turn-on when submerged underwater. This is based on pressure increase and not on the presence of water (i.e. the Perdix does not have wet contacts).

This feature is supplied as a backup for when you forget to turn on your Perdix. We recommend turning on manually before each dive to confirm proper operation and to double check battery status and setup.


The Perdix turns on automatically when the absolute pressure is greater than 1100 millibar (mbar). It can take up to 15 seconds for the Perdix to activate once 1100 mbar is exceeded. For reference, normal sea level pressure is 1013 mbar and 1 mbar of pressure corresponds to approximately 1 cm (0.4") of water.

So the Perdix will automatically turn-on when about 0.9 m (3 ft) underwater when at sea level. If at higher altitude, then the Perdix auto-on will occur at a deeper depth. For example, when at 2000 m (6500 ft) altitude the atmospheric pressure is only about 800 mbar. Therefore, at this altitude the Perdix must be submerged underwater by 300 mbar to reach an absolute pressure of 1100 mbar. This means the auto-on occurs at about 3 m (10 ft) underwater when at an altitude of 2000 m.

Summary: The guaranteed depth accuracy range is to 130 msw / 425 fsw. However, the case is rated to withstand 260 msw / 850 fsw. The depth sensor will continue to function to this depth, however, at reduced accuracy.

The pressure sensor that is used to determine depth is rated by the manufactured to be calibrated to a pressure of 14 Bar (about 130 msw / 425 fsw). It is designed to withstand pressures up to 30 Bar (290 msw / 950 fsw) . We find the sensors typically meet the EN13319 accuracy of +1m/-1.5m to about 190 msw / 625 fsw. The sensors continue to function to at least 300 msw / 985 fsw .

The Perdix case is rated to a crushing pressure of 260 msw / 850 fsw. The limiting factor is not the strength of the case, but rather the bending of the window inwards which eventually impacts the internal electronics and LCD display. We have tested units to dozens of cycles to 350 msw with no leaking or case failures. However, the window bends enough to impact the LCD, leading to damage or cracking of the display.

The Petrel is rated to a crushing pressure of 300 msw / 985 fsw because of larger internal clearances due to its thicker design. The window thickness, and therefore deflection, is about the same on both the Petrel and Perdix.

There are only a few differences between Perdix and the Perdix AI.

The Perdix AI is capable of connection with a transmitter to display air integration information. The Bluetooth chip is Bluetooth Smart as opposed to Bluetooth Smart Ready. Additionally there are extra reporting features in Shearwater Desktop specifically for the Perdix AI such as displaying the tank pressure throughout the dive, your SAC rate, as well as Gas Time Remaining information.

The Perdix AI does use radio waves at a frequency of 38kHz.  Any source of interference such as some HID lights, camera strobes, scooters, or other high-powered electrical devices might emit interfering noise in this frequency range.  The primary solution to these problems is to keep the Perdix AI computer away from these noise sources as much as possible.  Modern LED lights are less likely to cause a noise problem.

Once paired the Perdix AI will remember the transmitter serial numbers until un-paired or changed, even with battery replacement.

The Perdix AI pairing to transmitters is via manual entry to ensure that the correct transmitter is paired for the safety of air pressure and gas time remaining displays.

AI will not affect the battery life of the Perdix AI when it is turned off.  If the Perdix AI has AI enabled, power usage when on will increase by a small amount (roughly 10%, but this will vary) with one transmitter and a little more with two transmitters.  If a transmitter is not being used, it is recommended that it be disabled (does not need to be unpaired) in the Perdix AI system menu.

The transmitters we supply are suitable for use with up to 40% O2 Nitrox.  The question of usage with 100% O2 has a complex answer because there is no widely recognized scuba diving standard for what constitutes suitability for oxygen service. Hypothetically, the transmitter could be used with oxygen if we describe it as Nitrox Ready, otherwise you should assume air only service.  The reason why we can't give you a simple unqualified "YES" is related to the associated risks when the circumstances of use are completely outside our control. To dive using oxygen requires you to make an informed decision to accept for yourself the risks of handling the oxygen.

Non-AI Perdix computers do not have the necessary hardware to support AI, and it is impractical to upgrade the hardware to add this support.  The non-AI Perdix will still continue to be sold for those divers who do not plan or wish to use AI.

The Perdix AI does support two transmitters used on tanks in a sidemount configuration, however, gas time remaining (GTR) calculations are only supported for one selected transmitter (diver’s choice).  Tank switching notifications are not supported in the initial firmware release.

The Perdix AI only supports two transmitters in the initial firmware release.  This decision was made to reduce screen clutter and simplify the user interface.

GTR is similar to No Decompression Limit (NDL) in that it is the time, in minutes, that you can remain at the current depth until a direct ascent would result in surfacing with the reserve pressure remaining.

This calculation includes the gas used for the ascent but does not include any safety or decompression stops. The GTR display becomes blanked if decompression stops are required (it will return once cleared), so the diver must ensure they have enough gas if they expect to have decompression obligations. The GTR is based on the currently measured Surface Air Consumption (SAC) rate, averaged over the last few minutes.

The GTR calculations on the Perdix AI are only for single-tank diving that does not require decompression stops.

GTR is a tool for no-stop (i.e. no decompression) diving. We do not recommend GTR as a tool for decompression diving. Decompressing diving involves significant pre-planning of gas reserves and typically requires multiple tanks and gas mixtures. The complexities due to managing multiple tanks and differing styles of gas management would make setup of GTR too complex for reliable use. We tried this during development, and experienced testers frequently made setup mistakes that resulted in incorrect GTR. Shearwater feels that GTR is a great tool for single-tank, no-stop diving, but unfortunately does not work well for more complex diving.

Shearwater recommends service of your dive computer every 2 years by an authorized service centre.

Please see our troubleshooting section here.

Try taking the battery out and leaving it out for at least 5 minutes. This should allow the transmitter to reset, and often solves a loss of communications.

Firmware Updates

Current Firmware Version: V87

Update instructions

Note: Updating the firmware will reset the decompression tissue loading.

  1. Ensure that you have the latest Shearwater Cloud installed
  2. In Shearwater Cloud, go to Dive Computer > Update Firmware...
  3. On your Perdix, navigate to Start Bluetooth or  System Setup > System Setup > Load Upgrade, depending on your firmware version
  4. Shearwater Cloud will detect your Perdix and select the latest available firmware.
  5. Follow the instructions in Shearwater Cloud to select your firmware language and begin the update.

Getting Firmware Files

The easiest way to update your firmware is to download the new Shearwater Cloud Desktop and select Dive Computer-> Update Dive computer.  Follow the instructions on the screen and Shearwater Cloud Desktop will handle the rest.

Support Request


    • For repairs, please contact your nearest Repair Center listed below via email or fill out this form for RMA shipping details when shipping to Canada
    • For sales inquiries, please contact your nearest regional sales representative office.
    • For customer support inquiries, please email
    • For cloud software, bluetooth connectivity and IT support inquiries, please email

    United States Repair Center

    DIVE-Tronix, LLC
    Richard Morton
    +1 858 775 4099
    Snohomish, WA, USA

    Asia Pacific Repair Centre

    United Kingdom Repair Centre

    Narked at 90 Ltd
    +44 1933 681255
    Northamptonshire, UK

    Thailand Repair Centre

    United States Sales

    Curt McNamee
    +1 425 418 1425
    Everett, WA, USA

    Asia Pacific

    Daren Marshall
    Regional Manager APAC
    +61 408 878 678
    LINE ID: @darenmarshall

    Scandinavian & Baltic Sales

    Rannva Joermundsson
    +44 7498 067388
    Cornwall, United Kingdom

    New Zealand Sales

    Canada and California Sales

    Simon Morris
    +1 604 669 9958
    Richmond, Canada