Deep Biomes — Subnautica 2 Biome Guide: Depths, Resources & Threats
High threatUpdated 2026-06-02
The deep biomes of Subnautica 2 represent the most dangerous and rewarding environments in the game. Unlike the sunlit Safe Shallows and Kelp Caves, the deep biomes below 200 meters test your oxygen management, vehicle depth ratings, and combat evasion skills. This guide covers every deep biome in the Early Access build: the Thermal Spires, Jellyshroom Caves, Deep Zone, and the entrance to the Lava Corridors. Understanding the deep biomes' resource layouts and creature patrol routes is essential for reaching the endgame content.
Thermal Spires (120–250 m)
The Thermal Spires are the first deep biome most players encounter, transitioning from the Grass Plateaus around 120 meters. This biome is characterized by towering geothermal vents that provide a reliable power source for bases and attract thermal-healing flora. Resources include large lithium, magnetite, and ruby deposits. The Thermal Spires host the Crushclaw — a medium-sized aggressive crustacean that ambushes from sediment — and juvenile Bonesharks. This is the safest of the deep biomes and the recommended location for a mid-game forward base.
| Biome | Depth Range | Key Resources | Primary Threat |
|---|---|---|---|
| Thermal Spires | 120–250 m | Lithium, Magnetite, Ruby | Crushclaw (Medium) |
| Jellyshroom Caves | 200–350 m | Deep Shrooms, Uraninite | Crabsnake (High) |
| Upper Deep Zone | 350–500 m | Kyanite, Crystalline Sulfur | Shadow Leviathan (Extreme) |
| Lava Corridor | 500–700 m | Nickel, Ion Crystals | Lava Lizard (High) |
Jellyshroom Caves (200–350 m)
The Jellyshroom Caves are a vast underground cavern system illuminated by bioluminescent flora. Navigation is challenging due to the cave geometry — multiple vertical shafts connect different cave pockets. Crabsnakes hide inside the jellyshroom stalks and strike when players swim too close. The deep biomes here include the only natural source of Deep Shrooms, essential for high-capacity batteries. Uraninite deposits are abundant, making this a key stop for reactor fuel. Build a small scanner outpost at the cave entrance to map the complex tunnel system before exploring deeper.
Deep Zone and Lava Corridor (350–700 m)
The Deep Zone is where the most dangerous deep biomes begin. At 350 meters, the ambient light fades to near-total darkness, requiring vehicle floodlights or the Seamoth sonar upgrade. The Shadow Leviathan, the apex predator of the deep biomes, patrols the upper Deep Zone canyon. Below 500 meters, the Lava Corridor opens into a network of volcanic tunnels with thermal vents that can damage the Seamoth if approached too closely. The Lava Corridor contains the rarest resources in the deep biomes: kyanite for thermal plant upgrades, nickel for Prawn Suit depth modules, and ion crystals for endgame batteries. The Prawn Suit with MK2 depth module is the minimum requirement for exploring these deep biomes safely.
FAQ
- What is the deepest biome in Subnautica 2 Early Access?
- The Lava Corridor is the deepest biome currently accessible, reaching approximately 700 meters. Deeper biomes like the Abyssal Trench and Crystal Caverns are planned for future updates.
- Do I need a specific vehicle for the deep biomes?
- The Thermal Spires can be explored with a Seamoth (up to 300 m default, 900 m with MK3). The Jellyshroom Caves require at least the Seamoth MK1. The Deep Zone and Lava Corridor require the Prawn Suit with MK2 or MK3 depth module.