For full instructions with pictures explaining the best way to remove and replace the O-ring, please click here.
Support & Downloads
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 annually at your nearest service center.
It is unnecessary to register your unit upon purchase. Every Shearwater unit is tracked with a unique serial number.
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 email@example.com to initiate the process.
Please include your name, address and phone number, description of your problem, your 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.
What type of batteries can I use in the Predator?
The recommended battery is the 3.6V Saft LS14500 battery.
Other 3.6V Lithium Thionyl-Chloride batteries are possible, but may not provide adequate performance. Many batteries of this type cannot provide enough current to run the Predator. Batteries should be rated to provide a continuous output current of at least 50mA. For example, the Saft LS14500C (note the “C”) does NOT work because it is only rated to 25mA continuous.
How should I change the batteries on the Predator?
Instructions on how to change the batteries on the Predator can be found here: Predator Battery Kit Installation
How long should the battery last?
A Saft LS14500 battery should provide 90 hours of diving (on medium brightness) in addition to 1 year of standby time.
Higher screen brightness will drain the battery faster. On high brightness, about 60 hours of diving can be expected. The “Auto” brightness setting measures the ambient light to adjust the brightness for the best balance of battery life to screen readability.
If you aren’t getting the expected battery life, see the next item.
I am getting a lot of low internal battery warnings, even with new batteries. What is wrong?
You should be getting 60 to 100 hours of battery life on a Saft LS14500 battery.
Lower battery life could be caused by a few reasons:
- Wrong battery type. The recommended battery type is the Saft 3.6V LS14500. Other Lithium Thionyl Chloride batteries may not provide enough current for proper operation.
- Poor contact in the battery holder. Some holders do not squeeze the battery tight enough. These low battery warning often occur during the dive. A small kit is available free of charge to fix this problem. Please contact Shearwater (firstname.lastname@example.org) if you think you are having this problem.
- Battery passivation. This is an insulating layer that grows on the lithium anode during periods of storage, especially at high temperatures. The insulating layer burns off once the Predator is turned on, but the voltage drops during this time. If you see a single low internal battery warning after installing a new battery or after a period of storage, then this may be the cause.
- Other damage. It is possible your Predator is damaged and may need repairs. Contact us for support.
The Bluetooth connection is not working. What can I do?
See our Bluetooth Troubleshooting Guide.
How do I update the firmware?
Instructions for updating the firmware are available in the manual.
Why don't you make an app for my Ipad or Iphone? That would be awesome.
Yes, many divers are using Ipads or Iphones and they would make a good dive logging platform. Unfortunately, Apple requires an Apple Authentication Co-processor to establish a Bluetooth connection, and the Predator does not have this hardware. Apple products now allow connections without the Authentication Co-processor, but only with the new Bluetooth Low Energy specification, and again the Predator does not support this.
However, some third-parties are now working on Android apps that download directly from the Predator, so dive logging on tablets or smartphones should be available soon.
Note that Mac laptops and desktops are supported, only the mobile iOS products are not.
I don’t like your Desktop Dive Log program, how can I export my dives to another program?
The Predator is now supported by several third-party dive log programs, and we are working on getting more third party support. Many of the third-party programs provide direct download of dive logs via Bluetooth.
- JDiveLog (free, open source, direct download): http://www.jdivelog.org
- MacDive (Mac only, direct download): http://www.mac-dive.com
- DivePal (Requires log in, direct download): http://www.ediving.us/divepaldownload.php
- Diving Log (PC Only, no direct download, imports .swlogdata files): http://www.divinglog.de/english/home/index.php
- Subsurface (PC/Mac/Linux, free open source, direct downloads): http://subsurface.hohndel.org/
What kind of O2 Sensors can I use?
The Predator expects galvanic O2 sensors of the 10mV in air type. It assumes the sensors have linear response to PPO2 and have internal temperature compensation.
I am having problems calibrating. What can I do?
- Always follow the instructions provided by the rebreather manufacturer and training agency when O2 sensors.
- Cable and connector problems are also a common cause of failed calibrations.
- Failed or dying O2 sensors may fail to calibrate properly. Follow the replacement schedule as specified by the sensor manufacturer, the rebreather manufacturer and your training agency. Also, be aware that galvanic O2 sensors can be easily damaged by shock (e.g. when dropped).
- The Predator expects the mV output of the cells to be within 30mV to 70mV in 100% O2 at 1 atmosphere. These mV limits are scaled automatically with pressure changes and the Cal FO2 setting. If the measured mV is outside of the limits, that sensors will fail to calibrate.
I am getting strange or intermittent PPO2 readings. What should I do?
Cables and connectors are the most common points of failure. Inspect cables and connectors carefully. Try to isolate problems. For example, trying a new cable may help.
What is the pin-out of the Fischer connector?
How do I maintain the Fischer connector?
Have a look at our Fischer maintenance guide.
Is PPO2 displayed in absolute atmospheres or Bar?
The Predator displays PPO2 in absolute atmospheres (ata).
- 1 ata = 1013 millibar = 1.013 Bar
The difference between Bar and ata is only 1.3%, so for practical purposes the displayed PPO2 values can be considered either ata or Bar.
I calibrated with the Fraction of O2 (FO2) set to 98%, but after calibration the PPO2 reads differently (for example, 0.96). Why?
The Predator automatically adjusts the calibrated PPO2 to adjust for variations in current barometric pressure (due to altitude or weather). PPO2 is dependant upon ambient pressure, so the calibrated PPO2 will not always match the Fraction of O2 in the calibration gas.
For example, say we are at sea level (normally 1 atmosphere or 1013 millibars), but a low pressure weather system has the barometric pressure reading 990 millibars. If we calibrate with an FO2 of 98%, then the expected PPO2 is (990/1013) x 0.98 = 0.96. So after calibrating, all three sensors in this case would read 0.96 (not 0.98).
This is the correct way to calibrate PPO2. However, if this difference drives you crazy or you want to match another dive computer that does not adjust for barometric pressure, then set the "Display Setup->Altitude" setting to "SeaLvl". This will assume that surface pressure is always 1013 millibars, and your calibrated PPO2 will match the FO2. Note however, that this is actually an incorrect calibration and you are introducing error into your PPO2 measurements by doing this. DO NOT use the "SeaLvl" setting when diving at altitude. That is, when diving at altitude above sea level, set the Altitude setting to Auto.
How often should I calibrate my O2 sensors?
You should follow your training agency and rebreather manufacturer guidelines regarding calibrations.
In the absence of these, we can offer what we believe to be best practices:
- Always calibrate when a new sensor is installed.
- Calibrating every dive is unnecessary and can actually mask the decline of dying cells.
- Better than frequent calibration is infrequent calibration (perhaps quarterly), but coupled with frequent verification of calibration accuracy.
- Calibration accuracy should be verified for every dive.
- Verification of accuracy should be done at multiple points, ideally with one point above a PPO2 of 1.0.
- For example, verify that the sensors read close to 0.21 in air (at sea level, adjust expected value if at altitude). A pre-dive flush of O2 should show the sensors come close to 1.0. Verifiying above 1.0 can be done by stopping to flush with O2 at 6m during the descent. Alternatively, small pressure chambers are available for testing cells up to a PPO2 of 1.6 on the surface.
The reason verification should be performed above a PPO2 of 1.0 is that O2 sensor current limiting is a common failure mode of these sensors as they age. Current limiting can cause a sensor to behave linearly below a PPO2 of 1.0, but then taper off quickly above 1.0.
Also, CCR divers should always use at least 2 independent PPO2 displays. Calibrations should not be done on both displays at the same time (unless new sensors are being installed, in which case both must be calibrated). When performing the calibration, there is a risk of making a mistake, resulting in an inaccurate calibration. If you perform both calibrations at the same time, both will be wrong and with this error potentially undetectable. If calibrations are done on different days, you still may not know which is correct, but at least you will notice the difference, allowing you to call the dive or bail out to open circuit (Of course if you had verified the accuracy of the calibration, you wouldn’t have gotten into such a situation).
Why don't you use two-point PPO2 calibration?
We do not believe two-point calibration offers any benefit and has some distinct drawbacks over a one-point calibration.
- Two-point calibrations are more complex and time consuming, resulting a higher chance for mistakes.
- Two-point calibrations can mask some types of cell faults.
We believe the best approach is a one-point calibration WITH frequent verification of calibration accuracy.
Frequent verification of calibration accuracy is critical. Verification should be done at a minimum of two known points, ideally with one point above a PPO2 of 1.0. Achieving a PPO2 above 1.0 can be done by flushing with O2 at 6m during the descent or by using small pressure chambers that are available for this specific purpose.
Is a bungee mount available?
Some users also have clever ways of adding bungies to the stock mounting plate. Search forums for details.
To what depth is the Predator rated?
The depth sensor is rated to 130 meters (426 feet) of seawater. Deeper than this the accuracy is reduced. Testing has shown to accuracy to be within EN13319 limits to 190 meters. Absolute maximum pressure tolerated by the depth sensor is 300 meters.
The official rated crush depth is 185 meters. Predator and Pursuit dive computers have been taken to deeper depths without failure.
What maintenance is required for my Predator?
The Predator dive computer should be stored dry and clean. Do not allow salt deposits to build up on your dive computer. Wash your computer with fresh water to remove salt and other contaminants. Do not use detergents or other cleaning chemicals as they may damage the Predator dive computer. Allow to dry naturally before storing.
Do not wash under high pressure as it may cause damage to the depth sensor. Also do not remove the strap bracket assembly as it acts as protection for the depth sensor.
Store the Predator dive computer upright and out of direct sunlight in a cool, dry and dust free environment. Avoid exposure to direct ultra-violet radiation and radiant heat.
Why does my rebreather controller show “?” for the external battery?
The External Solenoid Battery is only sampled when the solenoid is on. The reason this is done is that an unloaded battery might have a high terminal voltage, eventhough the battery is actually almost dead.
If the solenoid has not fired yet, the External Voltage will display as a yellow "?".
When I bailout to Open Circuit, why does the solenoid keep firing?
The solenoid keeps firing because it is the safest mode of operation. For example, what if the switch to OC was the result of accidental and unnoticed button presses. In that case you would definitely want the solenoid to keep operating.
If you need the solenoid to stop injecting O2 during a dive, you must externally isolate the solenoid.
What is the 0.19 Setpoint setting for?
The 0.19 setting will stop solenoid injections while setting up on the surface, downloading dive logs, or updating firmware. DO NOT use the 0.19 setting when breathing on the loop.
If a dive starts on the 0.19 setpoint, the Predator will automatically switch to the normal low setpoint.
What decompression model does the Predator use?
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 Other Downloads section.
Recommended reading is Clearing Up The Confusion About “Deep Stops” – Erik C. Baker, P.E.
What does the “GF99” display value mean?
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.
What does the “@+5” display value mean?
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.
Why does the depth reading on my Predator disagree with my other computer?
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 salt water make it heavier than fresh water. If two dive computers are using different densities of water, then their displayed depths will differ.
The water density is adjustable on the Predator. In the Advanced Config 1 menu, the Salinity setting can be set from 1000 kg/m³ to 1040kg/m³. A cubic meter of pure water has a mass of 1000kg. So what we are setting is the mass of salts dissolved in the water.
- Fresh Water = 1000kg/m³
- EN13319 = 1020 kg/m³
- Salt Water = 1025 to 1035 kg/m³
The EN13319 (European CE standard for dive computers) value is between fresh and salt and is the Predator default value. The EN13319 value corresponds to a 10m increase in depth for pressure increase of 1 bar.
The “Auto” brightness setting measures ambient light levels to adjust brightness screen brightness for the best balance of battery life and screen readability.
When ambient light is strong (in direct sunlight for example), the screen brightness must be increased. Unfortunately, this uses more battery power. In low ambient light, brightness is decreased to prolong battery life.
One situation where “Auto” does not work well is a silt out. The ambient is low, so the screen brightness gets reduced. However, in this case you would want higher brightness to shine through the silt. If you expect a silt out, a fixed brightness (for example Medium) would work better.
Fixed brightnesses also provide more predictable battery life. Expected battery life is 120 hours on Low, 90 hours on Med, and 60 hours on High. Not getting this battery life? See the Batteries section.
The Auto altitude setting automatically compensates for surface pressure variations due to altitude or weather systems.
The other option "SeaLvl" assumes that the surface pressure is always 1 atmosphere (1013 millibar).
The recommended Altitude setting is "Auto". So why have the SeaLvl setting? It is for CCR divers who always want the PPO2 calibration result to equal the FO2 of the calibration gas.
The "OC Only" option simplifies the Predator operation when doing Open Circuit dives. It removes all menu options related to CCR diving. This makes the Predator easier to use, and reduces the risk of mistakes.
This option is not available on all models.
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.
The size of the o-ring is ¾” x 3/32”.
Please see our troubleshooting section here.
Current Firmware Version: V63
Note: Updating the firmware will reset the decompression tissue loading.
- Ensure that you have the latest Shearwater Desktop installed
- In Shearwater Desktop, go to Dive Computer > Update Firmware...
- On your Perdix, navigate to Start Bluetooth or System Setup > System Setup > Load Upgrade, depending on your firmware version
- Shearwater Desktop will detect your Perdix and select the latest available firmware.
- Follow the instructions in Shearwater Desktop 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 Desktop and select Dive Computer-> Update Dive computer. Follow the instructions on the screen and Shearwater Desktop will handle the rest.