Subnautica 2 Inventory Upgrade: Expand Beyond 20 Slots
You start Subnautica 2 with 20 inventory slots, and there are three ways to expand: Portable Lockers found in wrecks add +15 slots each and can be dragged back to base, Biobeds in Colonist Bunkers permanently increase your capacity, and base lockers can be built once you have the Habitat Builder.
Last updated: September 5, 2026
The 20-Slot Starting Inventory
Twenty slots sounds reasonable until your first real resource run. A single trip for Titanium, Quartz, and Copper fills the grid before you've touched anything rare — and that's the moment you find a piece of Silver with nowhere to put it.
Because Silver gates the Standard Air Tank, and food/water items compete for the same space, inventory pressure is constant in the early game. The solution comes in three tiers, roughly matching your progression: salvage, permanent upgrades, then base building.
Slot discipline helps in the meantime. Re-scanning fragments of blueprints you already own yields raw materials, which is a free passive farm — but only pick up what you actually have room for. Drop bulk Titanium before rare metals, keep one slot free for quest items when following NOA waypoints to black box sites, and never let a full grid force you to abandon Silver.
Portable Lockers: +15 Slots from Wrecks
Portable Lockers are lootable storage containers found inside wrecks. Each one you claim adds +15 inventory slots — a 75% boost to your starting capacity from a single find.
- +15 slots each — the biggest single inventory jump in the early game.
- Found in wrecks — bring a Flashlight and watch for poison spores in wreck interiors.
- Draggable — Portable Lockers can be physically dragged through the water, so you can haul them back to your Lifepod or base to use as storage furniture.
On wreck expeditions, leave a "surface watch" at the entrance if you're playing co-op, and drag every Portable Locker you find back home. A row of salvaged lockers next to the Lifepod is a perfectly good early storage wall before you can build anything.
Biobeds: Permanent Capacity Increases
Biobeds are found in Colonist Bunkers and interacting with one permanently increases your inventory capacity. Unlike Portable Lockers, this is a character-level upgrade — it stays with you forever, through death and respawn.
Biobeds are part of the broader biomod system in Subnautica 2, where Adaptation Chambers and special stations grant permanent character improvements. Our Biomods guide covers the whole system, including the Old Complex near spawn and its Biomodule station. Note that in co-op, permanent character upgrades like Biobeds must be acquired by each player individually — see the Co-op Guide for details.
Base Lockers via the Habitat Builder
The long-term answer to storage is building your own. Base lockers require the Habitat Builder, which you unlock by scanning 2 broken fragments at the Welcome Center ruins southeast of the Lifepod (or the Gene Donor site backup). Full directions are in our Habitat Builder Location guide.
Once you can build, construct a small powered base — remember that no power means no oxygen inside — and line a wall with lockers. Organize them by material so crafting sessions don't turn into scavenger hunts. For structure costs and power setup, see the Base Building Guide.
⚠️ The Refund Bases Warning
This is the single most important storage-related warning in Subnautica 2, and it has burned countless players:
The Refund Bases option in the Escape menu destroys your base and permanently deletes every item inside its lockers. In co-op, the refund is global — it affects the shared base for everyone. Always empty every locker before refunding a base, and never press it to "move" a base.
If you want to relocate, deconstruct structures individually with Q (full refund) or move them with F instead. Those methods are safe; Refund Bases is not.
Inventory Upgrade FAQ
You start with 20 inventory slots. It fills up fast on resource runs, which is why expanding storage is an early-game priority.
Three ways: grab Portable Lockers from wrecks (+15 slots each, draggable back to base), use Biobeds in Colonist Bunkers for a permanent capacity increase, and build storage lockers at your base once you have the Habitat Builder.
Portable Lockers are found inside wrecks. Each one adds +15 slots, and they can be physically dragged through the water back to your base or Lifepod.
Refund Bases (in the Escape menu) destroys your base AND permanently deletes every item stored inside its lockers. In co-op the effect is global. Always empty your lockers before refunding a base.