Subnautica 2 Buddy System Hotfix 1 Fixes Saves, Powerplant Turbines, and Proximity Chat

A follow-up to Buddy System, not the May Hotfix 1

Steam names this release Buddy System Hotfix 1. That wording matters: it is the first follow-up patch to the August 19 EA 1.2 update, not a replacement for the original May 19 Early Access Hotfix 1 article. This page uses the longer name so searches for either patch land on the right fix list.

The patch is a stability and compatibility pass. It does not announce a new biome, vehicle, story chapter, or date for the larger roadmap expansion. Those remain separate roadmap questions.

Save files now carry build and branch information

Save files now record the game build number and branch. The goal is to stop an incompatible save from being loaded into an older build, which is especially useful when a player moves between the normal public branch and Steam Experimental. The update also repairs the save/version tooltip, adds clearer logging for a failed platform write, and removes an obsolete compatibility file.

Before testing a restore, update the game, confirm the branch, and copy the whole SaveGames folder. If a slot still looks missing, record the build and branch before changing cloud settings or renaming backup files.

Axum Powerplant Turbine recovery

The September 3 note fixes an issue where an in-progress Axum Powerplant Turbine disappeared or could no longer be completed. Affected saves should show the construction ghost again and can finish the building at no cost. Players reaching that point after the update use the normal required resources.

If the turbine is still absent, do not spend replacement materials first. Update, reload the save, confirm the current branch, and note the route and build state for a report.

Base and co-op fixes players will notice

• Refund Base: items stored on wall racks now return correctly when a base is refunded.
• Multiplayer furniture: exterior furniture is movable for clients, and leftover base-spawn data is cleaned up to reduce save bloat.
• Tadpole and Haul: attached players reliably receive oxygen, inventory sharing is blocked while riding, and the share prompt now dismisses after driving away. A death during inventory sharing also has a fix.
• Base movement: currents no longer affect players sheltered inside bases, and completed construction ghosts no longer linger in saves.
• Voice chat: the push-to-talk input path for Proximity Chat is fixed. Every player should still match the same updated build before testing a mixed-platform session.

Creature, tool, and UI cleanup

Collector Leviathan pathing is improved in the lower canyon areas and its collision detection is tighter. The tracker detection radius is larger, Water Slug breath markers now appear only when the slug is physically in the world, and a collision issue blocking interaction with the Scout Ray chassis carry point is fixed.

The remaining fixes are small but useful: localization for PDA and Databank text, translated Jegna and Grace names, a character-select softlock, skewed distant alignment guides, Moonpool shrink-mode collision checks, analytics-toggle state, and more reliable compile and crash diagnostics.

What to do after installing

1. Let Steam finish the update, then restart the client if the new build does not appear.
2. Disable, remove, or uninstall mods before launching. Unknown Worlds repeats that the latest hotfix may cause mod crashes or unexpected behavior until creators update their work.
3. Back up the local save folder, especially before switching to Experimental or attempting a restore.
4. For co-op, update every player and compare the branch/build before changing NAT or router settings.

Official source and site response

The source for this summary is the official Steam announcement for Subnautica 2 Early Access Buddy System Hotfix 1, including its September 3 update. Sub2Wiki added a dedicated patch page, refreshed the update and known-issues desks, and carried the save, Powerplant, Refund Base, co-op, and Collector Leviathan notes into the pages players use to act on them.