Support & Downloads



The downloads for the Perdix are found HERE.

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.

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:

Yes, the Perdix saves the decompression tissue loading in permanent (non-volatile) memory every 16 seconds when on, and every 5 minutes when off. After a battery change the tissue loading will be restored to the last saved value.

If the battery is removed shortly after a dive but then reinstalled some time (days) later, the residual inert gas loading will be restored even though your body will have returned to equilibrium values. If it has been more than 4 days since your last dive, it is safe to reset the tissues. Otherwise, do not reset the tissues and simply accept the higher conservatism for the next dive. Quick battery changes (battery out less than 10 minutes) do not suffer this problem, and the tissues should not be reset.

Battery Changed

The standard decompression model is Bühlmann ZHL-16C with Gradient Factors. Also, the VPM-B decompression model is available by purchasing an unlock code. More information can be found in the .

Recommended reading is Clearing up the Confusion About ‘Deep Stops - Eric C. Baker, P.E.

The GF99 value shows the current leading tissue inert gas super-saturation percent gradient as defined by the Bühlmann ZHL-16C decompression model. If that sounds confusing, then recommended reading is Erik Baker’s paper, “Clearing Up Confusing About Deep Stops”.

This value can be used as a rough measure of the current decompression risk. A value of 100% (Bühlmann’s originally allowed super-saturation limit) is now generally accepted to be too risky. The GF low and high conservatism settings are used to scale Bühlmann’s original limits to reduce risk of decompression sickness. The default GF low value of 30% limits the super-saturation gradient at the deepest stop. The default GF high value of 80% sets the surfacing limit. Between the deepest stop and the surface the GF limit is linearly interpolated.

The GF99 value shows the current super-saturation as a percentage of Bühlmann’s original limits. If no super-saturation exists, then the GF99 displays “On Gas”. Once a super-saturation exists, the GF99 is displayed in green. It switches to yellow when the GF99 exceeds the value defined by the GF conservatism settings. Above 100% it is displayed in flashing red.

In extreme conditions, decompression risk can be traded for operational risk by using the GF99 display. For example, in a low-gas situation or perhaps a bailout or injury, you may want to get to the surface faster, but not blow off all the remaining decompression stops. You could then violate the stop displayed by the Predator, and decide to follow a more aggressive GF99, say 95%. This will get you out of the water faster, at a higher risk of decompression sickness, while still remaining within some limits. Upon resurfacing, appropriate action for omitted decompression should be followed such as rest, surface O2, monitoring symptoms and contacting DAN or other diving medicine center.

Conversely, the GF99 value can also be used to add conservatism. For example, if you knew that you had been exposed to factors that increase decompression sickness risk such as exercising during the bottom time or being colder on deco than the bottom, then you could use this value to extend shallow stops. Of course, you could always just add a few minutes to your last stop, but this gives a quantitative measure to correlate with “how you feel” after the dive.

The @+5 (at plus five) feature shows the Time-To-Surface (TTS) in minutes if you were to remain at the current depth for 5 more minutes. The main screen NDL value can be setup to show @+5 once deco is required. The @+5 can be compared against the current TTS to provide a variety of information.

The @+5 can be used as a measure of how fast decompression is accumulating. For example, you could be on a wreck with a scheduled time to meet back at the boat. By looking at the @+5, you can tell how much more deco time staying 5 more minutes on the wreck would cost, and plan accordingly (keeping of course within gas quantity and other limits).

Also, the @+5 value can be used as a rough measure of on or off gassing and the current deco efficiency. For example, say you are decompressing from a deep dive where there is a nice reef at 50 feet. Once the 50 foot stop has cleared, it may not seem too appealing to just head up to the deco line to hang. If you look at the @+5 and it is 4 minutes less than the TTS, then this means you are getting about 80% deco efficiency, so you might decide to hang out to enjoy the reef a little longer. Once the @+5 has drawn equal with the TTS, you are no longer decompressing effectively. This means staying 5 more minutes will make the dive 5 minutes longer, but the deco stops won’t be any longer. This is helpful information in deciding when to head up.

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 offers a worldwide 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.

Shearwater will, at its sole discretion, repair or replace defective products covered under warranty.

Unauthorized repairs, accidental damage, or negligence are not covered by the warranty.

The warranty covers included accessories such as chargers and straps.


Do I need to register my computer for warranty?

No. The warranty is linked to the computer’s unique serial number.


Who do I contact if my computer needs a repair?

You can contact our support team directly at or fill out the RMA form (Return Merchandise Authorization) here:

You may also contact your closest authorized service center directly using the contact details at the bottom of the page.

Please do not return any products without first obtaining an RMA from the relevant service center.


How much will my out-of-warranty repair cost?

A computer that comes in for an out of warranty repair will need to be disassembled to properly test the components to determine the failure. Once the failure has been determined, we will be able to accurately calculate an estimate for the necessary repairs. Please note that to prevent usage of potentially non-functioning computers, if you decline the repairs, and wish to have the computer returned to you, it will be returned disassembled.


How long will the repair take?

Shearwater and its authorized service centers aim to finish warranty repairs and authorized out of warranty repairs within 5 working days of receipt.

Delays in repair time may result due to holidays, parts delays, and/or the requirement for the computer to be repaired at a different location.

Please contact the relevant service center for a more accurate timeframe.


What is Shearwater’s service shipping policy?

You are responsible for the cost of sending in the computer for repair. As a reminder, do not send your computer to any repair centre until you have obtained an RMA from that repair centre. For in-warranty repairs, the computer will be shipped back at no charge. For out of warranty repairs, the return shipping charge is included within the repair estimate. If you have an out of warranty repair that you choose to decline, you may ask to have the service centre destroy it or ship it back at your cost.


How often should I have my computer serviced?

Shearwater recommends a general service of your dive computer every 2 years by an authorized service center.


Does the warranty cover the rechargeable battery in my Teric/Peregrine?

It is important to follow the directions for charging/storage in the computer’s manual to ensure peak battery performance.

If the battery is not meeting performance specifications within the 2-year warranty period, it will be repaired free of charge. Variations to battery lifespan can be expected due to operating at extremes of the rated specification, such as high environmental temperatures or repeatedly fully discharging the battery.


Battery Leaks

Damaged caused by battery leaks in dive computers that use a user changeable battery is not covered under warranty. Shearwater recommends the use of a lithium battery such as the Energizer Ultimate Lithium 1.5v battery to reduce the chance of battery leaks. Leaving AA batteries (especially alkaline batteries) in devices for extended periods of time significantly increases the chance of damage from a battery leak.


DEMO & PRO Computers

Please note that the warranty with our Demo & Pro model computers are only available to the original purchaser. For demo models, this means the authorized demo centre that purchased the computer. For Pro models, this extends to the original instructor/dive professional that was confirmed at time of purchase. This warranty is absolutely non-transferrable as these models are not intended for resale.

Repairs/service can be performed on Demo and Pro models, but if you are not the original owner, there will be a cost for the service.

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.

No, the Perdix is a stand alone only product.

The Perdix does have a rebreather (CC) mode that uses internal fixed PPO2 setpoints. This is useful for calculating backup decompression schedules when diving a closed circuit rebreather.

The Petrel 2 will continue to be sold in the Fischer and DiveCAN models for connecting to a rebreather.

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.

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

Please see our troubleshooting section here.

To purchase the VPM-B upgrade you can contact any dealer from our dealer network, provide them with your serial number, and request to purchase the unlock code.

We recommend you remove alkaline batteries from your unit if you intend to store it for an extended period. Alkaline batteries have a tendency to leak when they have fully discharged.

Firmware Updates

Current Firmware Version: V93

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 and select Dive Computer-> Update Dive computer.  Follow the instructions on the screen and Shearwater Cloud 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

    France Repair Centre

    United States Sales

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

    Jens Rubschlager
    Southwest Region, USA

    Paul Sheahan
    +1 704 564 3831
    Florida, USA

    Asia Pacific

    Daren Marshall
    Regional Manager APAC

    Scandinavian & Baltic Sales

    Rannva Joermundsson
    +44 7498 067388
    Cornwall, United Kingdom

    New Zealand Sales

    Canada Sales

    Simon Morris
    +1 604 669 9958
    Richmond, Canada

    UK & Ireland Sales