Subnautica: Below Zero is one of the most atmospheric survival games ever made, and the modding scene has only made it better. But there’s a catch that trips up a lot of new modders in 2026: the modding stack changed completely after the game’s 2.0 “Living Large” update, and most older guides still tell you to install tools that no longer work. This guide fixes that. We’ll cover the honest truth about how Below Zero modding works, the correct modern setup (BepInEx + Nautilus, not QModManager), and a categorized list of the best mods worth installing.
First, an honest reality check: Below Zero is single-player
Before you go looking for a “modded server,” here’s the thing you need to know: Subnautica: Below Zero is a single-player game. Developer Unknown Worlds Entertainment built it as the standalone follow-up to the 2018 original Subnautica, and the studio has stated it will not add official multiplayer or co-op — doing so would require rebuilding the engine or dedicating an entire team to the effort. There is no official dedicated server.
What that means practically: every mod for Below Zero is client-side. They install on your own machine, in your own game folder. There’s no server component, so “installing mods on a server” simply doesn’t apply to this game. (An unofficial community multiplayer mod for Below Zero does exist as a separate project, but it’s out of scope here and not something we’d build a hosting setup around.)
If you came here from our usual world of multiplayer survival titles, this is the big difference. We do offer always-on hosting for the Subnautica universe where it applies, but Below Zero itself runs entirely on your PC, and so do its mods.
The modding stack changed: QModManager is dead, BepInEx + Nautilus is the standard
This is the single most important thing in this article, and the reason so many old tutorials will break your game. For years, the Subnautica modding world ran on QModManager (QMM) as the mod loader, paired with the SMLHelper API framework. That era is over.
The game’s 2.0 “Living Large” update broke the old modding ecosystem. QModManager was never updated for 2.0 — QModManager 4.4.4 is the final version, now archived and supported only on the game’s Legacy branch. The modding community was directed to use BepInEx instead. After Living Large, mods stayed broken for a long time because everyone was waiting on a QMM fix that had gone unresolved for years; retiring QMM removed a middle step and gave modders more flexibility through BepInEx directly.
SMLHelper was discontinued too. Its modern successor is Nautilus, built purely for BepInEx. Critically, Nautilus and SMLHelper are mutually incompatible — you use one ecosystem or the other, never both at once. In 2026, that means: BepInEx + Nautilus.
Do not install QModManager for the current game version. If a guide tells you to, it’s outdated. The only reason to touch QMM today is if you deliberately roll the game back to the Legacy branch in Steam to run old QMods — and for almost everyone, that’s not what you want.
The two pieces you actually need
- BepInEx — the bootstrapper/framework that loads mods into the Unity game. Below Zero needs a build patched specifically for it, not the generic BepInEx 5 release.
- Nautilus — the modern modding API (the SMLHelper successor). Most mods refuse to load without it. The file
Nautilus.dllmust sit inBepInEx\plugins\Nautilus\.
The recommended way to get BepInEx is “Tobey’s BepInEx Pack for Subnautica: Below Zero” (by toebeann, Nexus mod 344). It’s a preconfigured BepInEx bundle that works on Windows, macOS, and Linux (including SteamOS / Steam Deck). It bundles convenience utilities — a loading splash screen, an audio patcher, a legacy “Subnautica Config Handler” for backward compatibility, and diagnostic logging — so you don’t have to assemble BepInEx by hand.
Where to get mods
- Nexus Mods — the primary host:
nexusmods.com/subnauticabelowzero - Thunderstore — the community mod database for Below Zero:
belowzero.thunderstore.io
How to install mods (install order matters)
The golden rule: BepInEx pack → Nautilus → individual mods, in that order. Get the foundation in place before you add anything on top.
Method A — Vortex (easiest, Windows)
- Install the Vortex mod manager (Nexus Mods’ official tool) and update it fully.
- On each mod’s Nexus page, click the Vortex button to install. Vortex handles file placement for you.
Method B — Manual
- Close the game completely.
- Find the game folder via Steam → Browse local files (the folder is named
SubnauticaZero). - Extract the BepInEx pack zip directly into the game folder, merging contents.
- Launch the game once to generate config files, then verify success by checking
BepInEx\LogOutput.log. - Place Nautilus so that
Nautilus.dlllives inBepInEx\plugins\Nautilus\. - Place each mod in
BepInEx\plugins\(typically in its own subfolder). When unpacking a mod zip, use “Extract Here,” not “Extract All.”
The resulting folder layout should look like this:
SubnauticaZero\
├─ Subnautica Below Zero.exe
├─ winhttp.dll (from the BepInEx pack)
├─ doorstop_config.ini (from the BepInEx pack)
└─ BepInEx\
├─ LogOutput.log (generated on first launch — check this)
└─ plugins\
├─ Nautilus\
│ └─ Nautilus.dll (required by most mods)
└─ YourModName\
└─ YourMod.dllPlatform notes: macOS users are steered toward gib, a CLI automation tool. Linux and Steam Deck users install manually with a specific Wine configuration. Tobey’s pack supports all three platforms, but the non-Windows paths take a little extra setup.
The best Subnautica: Below Zero mods (our picks)
A quick honesty note: “best” is opinion. The rankings below draw on a published “best of” list from TheGamer plus download-popularity where a source supports it — treat them as editorial picks, not objective fact. All of these mods are real and verifiable on Nexus Mods, and most of them require Nautilus to load. Always double-check the current author handle, mod ID, and that the latest version targets your game build before installing.
Quality-of-life mods
| Mod | Author | What it does |
|---|---|---|
| EasyCraft | newman55 | Auto-crafts blueprints by pulling ingredients from nearby storage. Ranked #1 by TheGamer — our top quality-of-life pick. |
| Advanced Inventory | newman55 | Expands inventory and adds hotkeys to move all items at once. |
| More Quick Slots (Nexus mod 18) | — | Raises quick slots from the default 5 to 10; v2+ lets you bind slots from the Options menu without restarting. |
| SnapBuilder – Snap-to-Grid (Nexus mod 57) | toebeann | Snap-to-grid base building: press a key to snap structures into place, with configurable rotation and snap modes. Also on Thunderstore. |
Map & scanner mods
- The Map Mod (newman55) — Adds a customizable map plus a player marker to the PDA. You can explore with fog-of-war or reveal everything for fast travel. It’s among the top-3 most downloaded Below Zero mods, and for good reason — Below Zero’s icy world is easy to get lost in.
- Better Scanner Room BZ (Nexus mod 43) — An improved, customizable Scanner Room derived from QMultiMod features, with a “Purple Edition (Nautilus)” variant available.
Vehicle mods (the Seatruck and friends)
- Seatruck Storage (Senna) — Adds two storage lockers to the Seatruck’s main cabin, so your mobile base actually carries gear.
- Seatruck Speed Upgrades (Senna) — Three upgrade tiers that raise Seatruck speed to 150%, 200%, or 250%. A favorite for cutting down long underwater commutes.
- Better Seaglide (ihatetn931) — Customize the Seaglide’s color and light cone, and add a boost.
- Moon Pool Vehicle Repair (Cookie / ahk1221) — Dock a vehicle in the Moonpool to auto-repair and recharge it.
Cosmetic mods
- Sleek Bases (AlHazrad) — Updated base floor and glass textures for a cleaner, more modern look.
- Subnautica Pets (Oli Ollerenshaw) — House creatures such as Snow Stalkers inside your base. Pure flavor, very fun.
Required utilities & dependencies
| Mod | Role |
|---|---|
| Nautilus (BZ) — Nexus mod 373 | The core modding API, required by most mods. Install this right after BepInEx. |
| Tobey’s BepInEx Pack — Nexus mod 344 | The preconfigured loader foundation (see the setup section). Windows, macOS and Linux/Steam Deck. |
| BepInEx ConfigurationManager | An in-game config editor UI for BepInEx 5 mods. Handy for tweaking mod settings without editing files by hand. |
If you want the deeper how-to for the Subnautica family of games — install walkthroughs, troubleshooting and config references — our Subnautica documentation hub is a good companion to this list.
Frequently asked questions
Can I run Subnautica: Below Zero mods on a server?
No. Below Zero is a single-player game with no official multiplayer or dedicated server. All mods are client-side, installed in your own game folder on your own machine.
Should I install QModManager?
No — not for the current game version. The 2.0 “Living Large” update broke QModManager; version 4.4.4 is the final release and only works on Steam’s Legacy branch. The modern stack is BepInEx + Nautilus. Older guides recommending QModManager are outdated.
What’s the difference between SMLHelper and Nautilus?
SMLHelper was the old API framework that paired with QModManager and has been discontinued. Nautilus is its modern successor, built purely for BepInEx. The two are mutually incompatible — use Nautilus, not SMLHelper.
What order do I install everything in?
BepInEx pack first (Tobey’s pack is the easy option), then Nautilus, then your individual mods last. Launch the game once after installing BepInEx to generate config files and check BepInEx\LogOutput.log to confirm it loaded.
Do these mods work on Steam Deck or Linux?
Yes. Tobey’s BepInEx Pack supports Windows, macOS, and Linux including SteamOS / Steam Deck. Linux and Steam Deck users install manually with a specific Wine configuration, and macOS users use the gib CLI tool to automate setup.
Why do most mods fail to load?
The most common cause is missing Nautilus. Most Below Zero mods refuse to load without it, and Nautilus.dll must be in BepInEx\plugins\Nautilus\. Also make sure you used the BepInEx build patched for Below Zero rather than the generic BepInEx 5 release.
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