Petrel and Perdix Firmware V34 Release Notes

A note on models

The Petrel, Petrel 2, and Perdix share a common firmware base. Due to hardware differences not all features are available on all models. The following changes apply to all models unless otherwise noted.

Listing of changes in Firmware v34



The ‘OC/CC’ mode has been renamed to ‘CC/BO’, where BO means bailout. Purpose is to clarify that OC/CC mode was never intended to be used for purely OC dives. Using the OC/CC mode for OC dives results in sub-optimal operation. This change clarifies the CC/BO mode is for closed circuit dives, with open circuit bailout. When diving OC, the mode should be set to either “OC Tec” or “OC Rec”.[/span8][span4]


BO Mode2“OC/CC” mode renamed to “CC/BO” for clarity of purpose[/span4]



(Perdix only): A custom image can be used as the Perdix startup splash screen. The size image size must be 320x240 pixels. Shearwater Desktop version 2.5.4 or higher is required to upload images. [/span8][span4]JohnnyAdd a custom startup image to the Perdix[/span4]


Better dive log page navigation. Allows moving backwards and forwards through the pages of dive logs (previously could only move forward or exit).



The gas will display in flashing red when its PPO2 is outside of a safe breathing range (i.e. below the min PPO2 or above the max PPO2 setting).
In CC mode, this warning refers to the diluent only. The breathing loop PPO2 may be in a safe range, but if the diluent is unsafe to breathe directly then the gas will be red. Note that other warnings exist to warn when the breathing loop is outside of a safe range.



unsafe dil
The CC diluent is red to indicate it is unsafe to breathe directly (PPO2 > 1.60)



Units of depth and temperature can be set independently. Depth can be set to feet or meters. Temperature can be set to °F or °C.


∆+5 (Delta + 5 minutes) is added as an option on the configurable center row, configurable bottom row, and ‘NDL display’ replacement. ∆+5 is the difference in the time-to-surface (TTS) if you remain at the current depth for 5 more minutes. This value can be positive or negative. For example, a ∆+5 of +10 would mean that staying 5 more minutes at the current depth would result in 10 more minutes of decompression stops.
∆+5 is similar to @+5, but the @+5 value shows the entire TTS while the ∆+5 only shows the difference from the current TTS.


When editing the dive number for the next recorded dive, the menu is now named “Next Log=” and you enter the value for the next dive. Previously you would enter the number of the last dive and the next dive would be this value plus one. The new method is more intuitive and is better described by the menu name.


Added a method to recover deleted dive logs. In the ‘Dive Log’ menu, there is now a ‘Restore Mode’ option. Setting this to “ON” allows either a “Restore All Logs” option or restoring individual logs (View the log list, deleted logs will be grayed out. Enter into the log view then the edit page will have an undelete option). After the unit is turned off then back on, this option will be reset to “OFF”.


When viewing the “TISSUES” bar graph, the display will not timeout back to the main screen.


Corrected the issue which the dive log was not shown properly when screen is flipped. This bug only affected the Perdix model.

Download the Entire v34 Release Notes

8 Responses

  1. Petrel – firmware v34
    can’t find a way to setup ∆+5 (Delta + 5 minutes) in a center row as it’s only available as NDL display option.
    List of ovailable options for a left/right center row: none, Max depth, Avg depth, @+5, Ceil, GF99, CNS, Clock, DET, TEMP, Timer. no ∆+5

    • Avatar Tyler Coen

      Hi Vlad, Unfortunately this is an oversight error on our part. In v34 on the original Petrel, the ∆+5 is not available on the center or bottom row configurable location. Like you noticed it is available as the NDL replacements. For the Petrel 2 and Perdix it is available in all locations. We will fix this on the next release. Sorry about the inconvenience.

  2. CHANGE : When viewing the “TISSUES” bar graph, the display will not timeout back to the main screen.
    Thanks for that : i was waiting for that option :-))

  3. NEW FEATURE: ∆+5 (Delta + 5 minutes)
    Before, I used the @+5 feature as NDL replacement and was happy with it.
    Today, I checked the new ∆+5 which makes it even much easier to check how fast deco is increasing.
    Thank you very much for this new feature (as well for all the other new features).

  4. Hallo, i noticed that with the new firmware the ascent speed arrows rise very fast also if you ascent very slow suddenly the display show five arrows.

    • Avatar Shearwater Research

      I will report this to our engineering department for review.

      • I noticed the same problem with my Petrel2. Please keep me informed in case any new information about this problem is available. Thanks a lot. Mark

      • Hi, as stated the ascent graph has a bug, goes straight to 7 (petrel 1), it does go yellow on all slightly fast ascents though, without an increase in number of bars displayed.

        Can you put me on a mail list for an update please? I use my Petrel daily, and this is a bit annoying if I’m in the blue with clients!