2026-05-15
Subnautica 2 Multiplayer Co-op Guide: Fix Lag, Share Saves & Connect
Everything you need to know about 4-player co-op in Subnautica 2 — how to connect, share save files, and fix common lag and connection errors.
How to Start Co-op
From the main menu, select Multiplayer and either host or join a session using a room code. Up to 4 players are supported.
Sharing Save Files
The host owns the save. Guests' progress is saved on the host's machine. If you want to continue without the host, export the save via Settings → Save Management.
Fixing Lag & Connection Errors
High Ping (>200ms): Ensure the host has port 7777 open (UDP). Use a wired connection if possible.
"Failed to Connect": Verify that your firewall allows Subnautica 2 through. Try restarting the lobby.
Unreal Engine 5 Stuttering: Disable shader pre-compilation in graphics settings. Set texture streaming pool to Low if VRAM is under 8GB.
Desync Issues: All players should be on the same game version. Check Steam for updates.
Recommended Co-op Roles
- Diver 1: Scout ahead, mark coordinates - Diver 2: Resource gatherer - Engineer: Base building and fabrication - Support: Medical, oxygen management
Need to find an exact coordinate?
Open Interactive Map →