ATMOS releases firmware updates for the MISSION3 that add functions and fix bugs. Recent examples are the freediving alerts and custom tables that can be configured in the ATMOS App, which need firmware 1.108 or later. This article explains how the update works, what you need and where the official files are.
The app does not update the firmware
A common misunderstanding: the ATMOS App syncs your dive logs and settings, but it does not install firmware. MISSION3 firmware is installed with a computer and the USB Type-C charging cable, following the official ATMOS procedure. Plan the update at home, not on the boat.
What you need
A Windows or Mac computer, the USB-C cable that came with your MISSION3, a charged watch and the firmware package for the MISSION3. Use only the firmware that ATMOS publishes for the MISSION3; firmware for MISSION2 or MISSION ONE is a different product and does not fit.
Where to find the official files
Our Support and Downloads page links to the current MISSION3 firmware, the official step-by-step update guide and the release notes on atmos.app. At the time of writing (13 September 2026) the current version is 1.109. Check the release notes before you start, so you know what changes and whether the update affects settings you rely on.
Before you start
Charge the watch. Sync your latest dives to the ATMOS App first, so nothing is lost if something goes wrong. Note your gradient factors, alarms and freediving settings, and check them after the update. Follow the official ATMOS guide exactly; if the update stops halfway, do not unplug the watch, and contact us or your dealer.
After the update
Check the firmware version in the watch settings, re-pair with the app if it asks you to, and run through your dive settings once. Then it is back to the water.
Questions? See the FAQ or contact us.