I've been waiting for this one for years. Subnautica was one of those rare survival games that genuinely scared me – in a good way – and the single biggest complaint the community had was that you couldn't share the experience with anyone else. Nitrox tried to fix that, and credit to the modders who built it, but it was always held together with duct tape and prayers. Now Unknown Worlds is doing it properly.
Subnautica 2 enters Steam Early Access in May 2026, and for the first time in the franchise's history, multiplayer is baked into the game from the start. Not modded in. Not bolted on. Designed around it. I want to break down everything we know so far about hosting a dedicated server, what you should be preparing for as a server admin, and where the gaps still are.
What's actually confirmed about multiplayer
The headline number is four-player co-op. You and three friends exploring an alien ocean together – that's the pitch, and it's been confirmed across every piece of marketing Unknown Worlds has put out. The game also supports solo play for anyone who prefers to be terrified alone, which, fair enough.
Crossplay is in from day one. Steam, Epic Games Store, and Xbox Series X|S players can all connect to the same sessions. That's a bigger deal than it sounds – getting crossplay working at Early Access launch instead of bolting it on six months later means your friend group doesn't need to all be on the same platform.
The engine is Unreal Engine 5, which is a complete departure from the original's Unity foundation. That matters for server admins because UE5 has a much more mature dedicated server architecture than Unity does.
Dedicated server details – what we know
Native dedicated server support is confirmed. The server binary is distributed through SteamCMD under App ID 2327760, separate from the main game client. Anonymous login works, so you don't need to tie a Steam account to your server install.
The install command is straightforward:
steamcmd +login anonymous +app_update 2327760 +quit
From the server hosting community's early documentation, the configuration lives in Subnautica2_Data/Config/Internal_Server.cfg. The settings that have surfaced so far:
ServerName– your server's display nameMaxPlayers– capped at 4 for stable performance in the current EA buildServerPassword– exactly what you'd expectPersistentWorld– boolean toggle for keeping the world running between sessionsAutosaveInterval– frequency of world savesPhysicsTetherRadius– how far from a player the server calculates physics, set to 150 by default
Networking uses three ports:
| Port | Protocol | Purpose |
|---|---|---|
| 27015 | UDP | Game traffic |
| 27016 | UDP | Nexus Sync |
| 27020 | TCP | RCON / Admin |
Player data is tied to a "Level-Linked Character" system where blueprints and tech trees are associated with the server's UUID. If you change the UUID, player progression resets. That's worth knowing before you casually regenerate server identities during testing.
Hardware – the early picture
I want to be careful here because the game isn't out yet, and requirements will almost certainly shift during Early Access. But based on what's surfaced from the hosting community and the client-side specs on Steam:
The client minimum spec calls for an i5-8400 or Ryzen 5 2600 with 12 GB of RAM. Recommended is an i7-13700 or Ryzen 7 7700X with 16 GB. The game needs 50 GB of storage.
On the server side, early reports suggest you want a 4.0 GHz+ base clock – Subnautica's world simulation involves a lot of creature AI, physics for underwater movement, and base state calculations that lean heavily on single-thread performance. There's also a strong recommendation for NVMe storage because the world uses a voxel chunk system.
For four players, I'd tentatively budget 8–12 GB of RAM for the server process, though that number will probably move around as patches land during EA.
What server admins should prepare for
If you're the type who likes to be ready on launch day, here's what I'd have in order:
Get familiar with SteamCMD. If you've hosted any Source engine or UE-based dedicated server before, you already know the drill. If not, it's worth running through the basics now.
Have your firewall rules templated. UDP 27015, UDP 27016, TCP 27020. Write the rules now so you can paste them in when the binary goes live.
Plan your backup strategy early. Subnautica worlds are precious. People build elaborate bases, explore for hours, and develop real attachment to their world state. Automated backups from day one aren't optional.
Don't over-commit on player count. The config reportedly lets you push beyond 4, but Unknown Worlds designed the EA build for four-player co-op. Start at 4.
Expect frequent updates. This is Early Access. Early Access survival games get patched constantly, and each patch means updating the server binary, testing for save compatibility, and sometimes adjusting config values.
What we still don't know
I want to be honest about the unknowns, because some hosting guides gloss over these.
We don't have confirmed RCON command sets yet. Port 27020 is flagged for RCON/Admin, but what commands will be available at launch is anyone's guess.
Server-side modding support is unclear. The original Subnautica had a healthy modding scene through BepInEx and QMods, but dedicated server modding is a different beast.
Performance at scale is theoretical until people actually run it. The 4.0 GHz recommendation comes from community testing, not official documentation.
Hosting with LOW.MS
We'll have Subnautica 2 hosting available as soon as Early Access goes live. Instant deployment, automatic backups, web control panel at control.low.ms, DDoS protection, and support around the clock.
Keep an eye on our Subnautica 2 server hosting page. It'll go live the moment the game does.
If you've already read our earlier post – Subnautica 2: What We Know About 4-Player Co-op and Dedicated Server Hosting – consider this the more technical companion piece. That one covers the "why" of private hosting; this one is aimed at the admins who want to hit the ground running.
I'll update this guide once Early Access launches and we've had hands-on time with the actual server binary. Some of the details above will hold up. Some won't. That's the nature of pre-launch information, and I'd rather be transparent about it than pretend we have all the answers before anyone's actually run the thing.