Subnautica was the first major post-launch patch released by Unknown Worlds, primarily focused on quality-of-life improvements, bug fixes, and localization updates. Because it is an official game update, it typically installs automatically through your game launcher. How to Install Update 84
If you are playing on a modern platform, the update should be applied automatically without manual intervention. subnautica-update-84-installation-tutorial
: If your Steam client is open, it will automatically detect the update and begin downloading it. If it doesn't, right-click Subnautica in your Library, select Properties > Installed Files , and click Verify integrity of game files to force an update check. Subnautica was the first major post-launch patch released
: Once the download is complete, Steam will provide a file path (usually under Steam\steamapps\content\app_264710 ). You can move these files to a separate folder to run that specific version. : If your Steam client is open, it
If you are looking for Update 84 specifically to maintain compatibility with older mods or for speedrunning purposes, you can manually revert your game version using the Steam Console.
: Press Win + R and type steam://open/console .
: These launchers also handle updates automatically upon startup.