Lithium Hunting in Subnautica 2: Your Ultimate Guide to Finding It Early

Lithium is a critical resource in Subnautica 2, mainly used to craft plasteel ingots for upgraded air tanks and other advanced gear. However, it’s not available right away—you’ll need to brave warmer waters and unlock certain mutations before you can collect it safely. Below, we answer your most pressing questions about where to find lithium, when you can get it, and how to make the most of your scavenging trips.

1. What is lithium used for in Subnautica 2?

Lithium is primarily used to craft plasteel ingots, which are essential for building larger, better air tanks that let you dive deeper. Without a decent air tank, exploring dangerous biomes becomes nearly impossible. Later on, lithium also appears in recipes for vehicle upgrades and base modules, making it a mineral you’ll want to stockpile early. Even though its uses are limited at first, gathering a decent stash ensures you won’t be scrambling later when you need plasteel for advanced suit upgrades or the Seatruck’s depth modules. In short, lithium is one of those “gateway” resources—once you have it, many more possibilities open up.

2. When can you start collecting lithium?

Lithium doesn’t appear in the safe shallows or kelp forests where you begin the game. It only starts showing up once you venture into warm water biomes that are too hot for your starting character to survive without special mutations. To get there, you’ll first need to unlock the heat-resistance mutations—either by consuming specific flora or completing research. Once you have those, you can safely swim in waters around 40–50°C and begin your lithium hunt. Typically, this happens after you’ve built a basic base, crafted a seamoth, and explored a couple of biomes. The game’s progression naturally guides you to warmer zones around the time you need plasteel for upgrades.

3. Where is the best spot to find abundant lithium?

There is one standout location where you can harvest more lithium than you’ll need for a long time: the large thermal vents near the border of the Twisty Bridges and the Thermal Spires. This area is filled with geothermal activity, creating rocky outcroppings and scattered loose rocks that contain lithium. You’ll find deposits both on the seafloor and embedded in large rock clusters. A single trip can yield 10–15 units, enough for several plasteel ingots. The spot is also conveniently close to several early-game bases, so you can set up a small outpost or use a scanner room to mark the deposits. Just be careful of the heat and any aggressive fauna—a thermal blade can help with both.

4. How do you collect lithium without taking heat damage?

To collect lithium from warm waters, you absolutely need the heat resistance mutation. Without it, you’ll start taking damage the moment you enter these zones. The mutation can be acquired by either eating certain heat‑resistant creatures (like the Spinefish) or by researching thermal vents at a fabricator. Once unlocked, it becomes a permanent passive ability—no need to equip anything. Additionally, you can craft a thermal suit later for extra protection, but the mutation alone is sufficient for early collection. When you’re in the hot zone, keep an eye on your HUD temperature icon; if it turns red, swim to cooler pockets or use a thermal blade to quickly mine and retreat. Bringing a seaglide helps you cover ground faster and minimize exposure.

5. Are there any other locations for lithium?

While the thermal vent area is the richest early source, you can also find smaller amounts of lithium in deep shale outcrops scattered across deeper biomes like the Lost River and the Inactive Lava Zone. These areas are far more dangerous and require a prawn suit or advanced depth modules to explore. The shale outcrops look like dark, lumpy rocks and break open to reveal lithium along with other minerals like diamond or gold. However, because these zones are late‑game, most players stick with the thermal vent farm during mid‑game. Once you’ve cleared the vents, revisiting after a day or two will cause lithium deposits to respawn, so it’s a renewable resource—just slower than other nodes.

6. How much lithium should you stockpile for crafting?

A good rule of thumb is to collect at least 20 units of lithium early on. That’s enough to craft two plasteel ingots for a high‑capacity air tank and one for a vehicle upgrade module. As you progress, you’ll need more for the Cyclops shield generator, prawn suit drill arm upgrades, and thermal reactor modules. The thermal vent location yields about 15 per trip, so two trips should cover your early needs. After that, you can mine as needed. Because lithium respawns slowly, it’s wise to mark the spots with beacons and revisit every few in‑game days. Overstocking is rarely a problem—lithium doesn’t spoil, and you can always use it for base reinforcements later.

7. What tools do you need to mine lithium?

Lithium mineral deposits require the terraformer or a mining drill (prawn suit) to extract efficiently. In the early game, you can break open small lithium rocks with a standard knife, but the larger deposits—especially the ones that yield multiple units—need heavier equipment. The thermal vent area has both small scattered chunks and large nodes. For small chunks, a simple survival knife works, but for the big deposits you’ll want a seamoth with a drill arm or a prawn suit. Since you’ll be in warm waters, also bring a thermal knife (if unlocked) to combine heat resistance with cutting power. Don’t forget a habitat builder to set up a scanner room nearby—it will highlight all lithium within range.

8. Which mutations do you need to survive hot water?

The primary mutation required is the Thermal Tolerance adaptation, which you can obtain by consuming any of the following: a Spinefish (found in thermal vent areas), a Bladderfish after cooking it in a hot vent, or by scanning a thermal vent with a scanner. Each method unlocks a permanent ability to withstand temperatures up to 70°C. There’s also a secondary mutation called Heat Absorption that reduces heat damage further, but it’s optional for lithium mining. Focus on getting Thermal Tolerance first—it’s the key that opens the door to lithium farming. Without it, even approaching the thermal vent zone will force you back with burning damage. Once you have it, you can swim freely and gather all the lithium you need.