Subnautica 2 Biome Guide 2026: Every Zone — Resources, Dangers & What Depth You Need

I stumbled into the Blood Kelp Zone 8 hours in with a 200m-depth Seamoth and no rebreather. The PDA said 'Detecting multiple leviathan-class lifeforms.' I alt-F4'd and didn't play for two days. Here's exactly when and how to enter every biome.

Safe Shallow biomes (0-200m)

Safe Shallows (0-80m): Starting biome. Titanium, copper, quartz, creepvine seeds. Gasopods (passive unless you swim into their gas pods). Crashfish in sulfur plant caves (swim away — they explode on timer). Visit: immediately. Leave by: 2 hours in.

Kelp Forest (0-160m): Creepvine clusters, stalker territory. Stalkers grab metal salvage and teeth (essential for enameled glass). Drop metal salvage near stalkers — they'll 'play' with it and drop teeth. Creepvine seed clusters (lubricant, silicone rubber). Cave sulfur (crashfish nests). Visit: first hour. Danger: Stalkers (aggressive, 15 damage/bite — seamoth perimeter defense repels them).

Grassy Plateaus (50-200m): Red seagrass, sandstone outcrops (gold, silver, lead). Reefbacks (passive giants — follow them, they carry barnacles with copper/silver). Sandsharks (annoying but low damage — ram them with seamoth). Visit: 2-4 hours. Best early base location.

Mid-depth biomes (200-700m)

Mushroom Forest (100-250m): Giant mushroom trees. Lithium (on tree trunks and seafloor), Cuddlefish egg (rarest creature egg — one per game world), diamond (shale outcrops). Zero predators. Best lithium mining location. Visit: when you need lithium.

Sparse Reef (200-310m): Rubies, gel sacks, deep shrooms, blood oil. Zero predators. Essential for: aerogel (gel sacks + rubies), benzene (blood oil). Build a scanner outpost here. Visit: mid-game, before Lost River.

Jellyshroom Caves (160-300m): Entrance from Grassy Plateaus (cracked cave openings). Magnetite (thermal plants, upgrades), shale outcrops (lithium, diamond). Crabsnakes (hide in jellyshrooms — they ambush. Avoid the jellyshrooms = avoid Crabsnakes). Degasi base (abandoned seabase with PDA logs and decorative items). Visit: 5-8 hours, right after Seamoth depth Mk1.

Grand Reef (150-500m): Crystalline sulfur, nickel, gel sacks. Rubies (thermal vents). Degasi base (deepest Degasi seabase). Warpers patrol deeper sections. Anchored floaters (tether to gasopod-like creatures — don't get too close). Visit: mid-game, after Seamoth depth Mk2.

Blood Kelp Zone (200-600m): Blood oil (benzene crafting), deep shrooms, gel sacks. Warpers, Ampeels (electric eels — 20 damage on contact, EMP blast disables vehicles temporarily), Crabsquids (EMP blast — disables all electronics including lights, scanner, vehicle power for 3 seconds). Second Degasi seabase. Visit: mid-game, when you need blood oil and deep shrooms. Bring repulsion cannon for Crabsquids.

Dangerous biomes (400-1200m)

Dunes (100-400m): 6 Reaper Leviathans. Large resource deposits (drillable). Large wrecks with rare blueprints. Silver, titanium, quartz. Only visit with Prawn Suit drill arm. Stay on the seafloor — Reapers patrol mid-water. Mushroom Forest borders = relatively safe entry point.

Mountains (200-500m): 5 Reaper Leviathans. Large resource deposits, magnetite. Reapers are more aggressive here than Dunes — they'll chase you 300m. Visit only for endgame resource gathering. Bring stasis rifle.

Crash Zone (100-400m): Aurora wreckage perimeter. tons of metal salvage, cyclops engine fragments (decorative only in Subnautica 2), 9 Reaper Leviathans. Radiation suit required near Aurora. Visit: once for radiation leak repair, never again.

Endgame biomes (700-1700m)

Lost River (650-900m): Green brine pools (damage on contact — stay above them). Ghost Leviathan juvenile (one patrols the junction). Nickel, crystalline sulfur, uraninite (nuclear reactor fuel). Giant Cove Tree (thermal vents, no predators — best endgame base location). Disease Research Facility (story location). Visit: endgame, with Seatruck Mk2 and Prawn Suit.

Inactive Lava Zone (900-1300m): Sea Dragon Leviathan (spits lava, 85% damage to Prawn Suit, one-shots player without reinforced dive suit). Lava lizards (shoot lava rocks). Kyanite (required for final depth modules — drill large kyanite deposits with Prawn Suit). Lava Castle (Alien Thermal Plant — story location). Visit: endgame, Prawn Suit Mk1 minimum, Thermal Reactor upgrade recommended.

Lava Lakes (1300-1700m): Deepest biome. Sea Dragon Leviathan (second one patrols). Primary Containment Facility (final story location). Kyanite deposits everywhere. Ion cubes. Visit: endgame, Prawn Suit Mk2 required, Thermal Reactor mandatory (charges Prawn Suit from ambient heat).

Void (edge of map, 0-8000m): 3 Ghost Leviathan adults spawn instantly when you enter. No resources. No structures. Death. The PDA says 'Are you sure whatever you're doing is worth it?' It isn't.

Biome progression cheat sheet: Safe Shallows → Kelp Forest → Grassy Plateaus → Jellyshroom Caves → Mushroom Forest → Grand Reef → Blood Kelp Zone → Lost River → Inactive Lava Zone → Lava Lakes. In that order. Any other order and you'll meet a Leviathan before you have the tools to survive it.