Subnautica Biomes Guide
Planet 4546B has over 20 distinct biomes, each with unique resources, dangers, and secrets. Knowing where to go — and what to expect — determines whether you return with loot or become leviathan food. This guide covers every biome with detailed data tables.
Biome Overview Map (Depth Progression)
Surface (0m)
├── Safe Shallows (0–30m) ← Starter
├── Kelp Forest (10–70m)
├── Grassy Plateaus (20–100m)
├── Sparse Reef (30–120m)
│
├── Floating Island (surface) ← Above water
├── Mountain Island (surface) ← Above water
│
├── Jellyshroom Cave (150–300m) ← First deep biome
├── Underwater Islands (30–200m)
├── Mushroom Forest (50–250m)
│
├── Floating Islands Caves (150–300m)
├── Sparse Arctic (50–150m) ← Below Zero only
│
├── Blood Kelp Zone (200–450m)
├── Grand Reef (100–500m)
├── Deep Grand Reef (350–650m)
│
├── Lost River (400–1100m) ← Major biome transition
│ ├── Lost River Junction (700m)
│ ├── Lost River Bone Fields (750m)
│ └── Lost River Tree Cove (900m)
│
├── Lava Lakes (1000–1250m)
├── Inactive Lava Zone (800–1200m)
└── Active Lava Zone (1100–1500m)
Safe Biomes
Safe Shallows
| Stat | Value |
| Depth Range | 0–30m |
| Danger Level | ★☆☆☆☆ (None) |
| Predators | None |
| Vehicles | None required |
| Resource | Abundance | How to Collect |
| Titanium | Very High | Limestone Outcrops, Metal Salvage |
| Copper | Very High | Limestone Outcrops |
| Quartz | High | Seafloor pickups |
| Silver | Low | Sandstone Outcrops |
| Gold | Low | Sandstone Outcrops |
| Creepvine Sample | Medium | Cut kelp near border with Kelp Forest |
| Salt | Medium | Sandstone Outcrops |
| Acid Mushroom | Medium | Cave entrances |
| Lubricant | Craftable | From Creepvine Seed Clusters |
Points of Interest: - Lifepod 5 (your lifepod, center) - Lifepod 4 (wreck with Seaglide fragments) - Lifepod 3 (wreck with scanner room fragments) - 3 Cave entrances leading to Jellyshroom Cave - Thermal vent (for thermal power, small)
Exploration Tips: This is your home base biome. Resources are abundant but basic. Focus on gathering Titanium and Copper here — you'll need hundreds.
Kelp Forest
| Stat | Value |
| Depth Range | 10–70m |
| Danger Level | ★★☆☆☆ (Low) |
| Predators | Stalkers (20 damage, territorial) |
| Vehicles | None required |
| Resource | Abundance | Notes |
| Creepvine Sample | Very High | Cut tall kelp stalks |
| Creepvine Seed Cluster | High | Glowing yellow clusters |
| Titanium (wrecks) | High | 2 wreck zones with large salvage |
| Copper | Medium | Limestone Outcrops |
| Silver | Medium | Sandstone Outcrops |
| Stalker Teeth | Medium | Stalkers drop teeth when biting salvage |
Points of Interest: - Lifepod 17 wreck (Seamoth fragments) - 3 Metal Salvage wrecks - Stalker nest (area with many teeth on ground)
Stalker Tip: Stalkers are attracted to Metal Salvage. Drop a piece on the ground, lure a stalker to bite it, collect the dropped teeth. 5 teeth = 1 Enameled Glass.
Grassy Plateaus
| Stat | Value |
| Depth Range | 20–100m |
| Danger Level | ★★☆☆☆ (Low) |
| Predators | Sand Sharks (25 damage, ground-based) |
| Vehicles | None required |
| Resource | Abundance | Notes |
| Silver | Very High | Sandstone Outcrops |
| Gold | Very High | Sandstone Outcrops |
| Quartz | High | White crystals on seafloor |
| Lithium | Medium | Sandstone Outcrops (rare proc) |
| Copper | Medium | Limestone Outcrops |
| Table Coral | High | Coral structures (blueprints) |
Points of Interest: - Lifepod 6 wreck (Moonpool fragments) - Geothermal vents (thermal power) - 3 Wreck zones with Seamoth upgrades - Border with Jellyshroom Cave entrances
Sand Shark Tip: Sand sharks burrow in the red grass and ambush from below. Stay 3+ meters above the seafloor to avoid them. They can't climb.
Mushroom Forest
| Stat | Value |
| Depth Range | 50–250m |
| Danger Level | ★★☆☆☆ (Low) |
| Predators | None (one of the safest deep biomes) |
| Vehicles | Seamoth recommended (but not required) |
| Resource | Abundance | Notes |
| Lithium | Very High | Large deposits on ground |
| Magnetite | High | Glowing blue deposits |
| Acid Mushroom | Very High | Giant mushrooms |
| Uraninite | Medium | Caves at base |
Points of Interest: - Lifepod 13 wreck (Cyclops Hull fragments) - Degasi Seabase (small, with PDAs) - 2 Giant Mushroom Trees (navigation landmarks)
Why Go Here: Safest source of Lithium and Magnetite. Lithium is needed for Plasteel (endgame material). Magnetite is needed for Seamoth depth modules.
Floating Island
| Stat | Value |
| Depth Range | Surface (above water) |
| Danger Level | ★☆☆☆☆ (None) |
| Predators | None on island |
| Resource | Abundance | Notes |
| Marblemelon Seeds | 4 guaranteed | Best food/water source |
| Bulbo Tree samples | 6+ trees | Food and water |
| Lantern Tree samples | 4 trees | Food source |
| Purple Pineapple | 3 guaranteed | Craftable into tool |
| Coffee Machine | 1 | Free hot drinks |
Points of Interest: - Degasi Island Base (PDA entries, storyline) - 2 Small freshwater pools - Natural garden with all plant types
Critical Resource: Grab at least 2 Marblemelon seeds and 1 Bulbo Tree seed. Grow them in your base for infinite food and water.
Dangerous Biomes
Jellyshroom Cave
| Stat | Value |
| Depth Range | 150–300m |
| Danger Level | ★★★☆☆ (Medium) |
| Predators | Crabsnakes (35 damage, ambush from shrooms) |
| Vehicles | Seamoth (200m depth minimum) |
| Resource | Abundance | Notes |
| Magnetite | Very High | Only reliable source of Magnetite |
| Deep Shrooms | High | Blueprint unlock for Aerogel |
| Lithium | Medium | Rocky outcrops |
| Rubies | Low | Deep areas (250m+) |
| Uraninite | Low | Cave walls |
Points of Interest: - Lifepod 2 wreck (Grav Trap fragments) - Degasi Seabase (underwater, 250m deep) - 3 Entrance caves (from Safe Shallows, Kelp Forest, Grassy Plateaus)
Survival Strategy: Crabsnakes live inside the giant pink jellyshrooms. Stay in the center of the cave away from shroom tops. If a Crabsnake emerges, boost away in your Seamoth.
Blood Kelp Zone
| Stat | Value |
| Depth Range | 200–450m |
| Danger Level | ★★★★☆ (High) |
| Predators | Crabsquid (EMP), Ampeels (electric), Warpers (teleport) |
| Vehicles | Seamoth (300m+) |
| Resource | Abundance | Notes |
| Blood Oil | Very High | From Blood Kelp stalks |
| Deep Shrooms | High | For Aerogel |
| Gel Sack | Medium | For Aramid Fiber |
| Ruby | Medium | Deep areas |
| Uraninite | High | Caves |
Points of Interest: - Lifepod 19 wreck (Cyclops engine fragments) - Degasi Deep Base PDA - Blood Kelp trench entrance to Lost River
Survival Strategy: This biome is dark, deep, and full of aggressive creatures. Use Seamoth's perimeter defense system. Warpers will teleport you out of your Seamoth — dodge their projectile.
Grand Reef
| Stat | Value |
| Depth Range | 100–500m |
| Danger Level | ★★★★☆ (High) |
| Predators | Crabsquid (EMP), Warpers, Ghost Leviathan (juvenile, rare) |
| Vehicles | Seamoth (300m+), Prawn Suit recommended |
| Resource | Abundance | Notes |
| Ruby | Very High | Best ruby source |
| Gel Sack | High | Blue glowing balls |
| Deep Shrooms | Medium | Caves |
| Lithium | Medium | Deep areas |
Points of Interest: - Lifepod 7 wreck (Cyclops bridge fragments) - Deep Grand Reef entrance - Degasi Deep Base (PDAs, storyline) - Huge wreck with modification station fragments
Survival Strategy: Stay high (100–200m) to avoid most threats. Crabsquid EMP blasts disable your Seamoth for 5 seconds — extremely dangerous. Kill or avoid them.
Lost River
| Stat | Value |
| Depth Range | 400–1100m |
| Danger Level | ★★★★☆ (High) |
| Predators | Ghost Leviathan (juvenile, 3 spawns), River Prowlers, Lava Larvae |
| Vehicles | Cyclos or Prawn Suit (900m+ depth) |
| Resource | Abundance | Notes |
| Nickel Ore | Very High | Required for Cyclops depth modules |
| Crystalline Sulfur | High | From green brine pools |
| Uraninite | High | Caves |
| Kyanite | Low | Deep brine pools |
Sub-Biomes:
| Sub-Biome | Depth | Notable |
| Lost River Junction | 700m | 4-way intersection, Ghost Leviathan spawn |
| Bone Fields | 750m | Giant skeleton, River Prowlers |
| Ghost Forest | 800m | Blue brine, Ghost Ray spawns |
| Tree Cove | 900m | Giant tree, safe zone, Sea Dragon skeleton |
Green Brine Hazard: The green brine pools deal 5 HP/s damage and damage vehicles. Stay above the green. Use Prawn Suit jump jets to cross pools.
Lava Zones
Inactive Lava Zone
| Stat | Value |
| Depth Range | 800–1200m |
| Danger Level | ★★★★☆ (Very High) |
| Predators | Lava Lizards, Lava Larvae, Warpers |
| Vehicles | Cyclops + Prawn Suit (1300m depth modules) |
| Resource | Abundance | Notes |
| Kyanite | Very High | Required for depth modules |
| Uraninite | High | Lava cave walls |
| Magnetite | Medium | Deposits |
| Diamond | Medium | Drill deposits |
Active Lava Zone
| Stat | Value |
| Depth Range | 1100–1500m |
| Danger Level | ★★★★★ (Extreme) |
| Predators | Sea Dragon Leviathan (2 spawns), Lava Larvae |
| Vehicles | Prawn Suit (1700m module) |
| Resource | Abundance | Notes |
| Kyanite | Very High | Best source |
| Uraninite | High | Lavarock formations |
| Diamond | Medium | Drilling deposits |
| Ion Cube | 4 guaranteed | Endgame crafting |
Points of Interest: - Primary Containment Facility (endgame story location) - Thermal power plant - Alien Archways
Sea Dragon Survival: The Sea Dragon deals 80+ damage and breathes fire. Stay behind pillars when it attacks. Use Prawn Suit grappling hook to circle strafe.
Bottom Feeders & Void Biomes
Crater Edge (The Void)
| Stat | Value |
| Depth Range | 1000m+ (infinitely deep) |
| Danger Level | ★★★★★ (Instant Death) |
| Predators | Ghost Leviathans (adult, infinite spawns) |
Void Tip: There is NOTHING in the Void except death. If you see the water turn dark blue and the music changes, you've reached the edge of the map. Turn around immediately. Ghost Leviathans spawn endlessly and deal 100+ damage per bite.
Underwater Islands (Surface)
| Stat | Value |
| Depth Range | 30–200m |
| Danger Level | ★★★☆☆ (Medium) |
| Predators | Bonesharks (30 damage), Warpers |
| Resources | Lithium, Copper, Titanium, Bone Shark Teeth |
Biome Exploration Checklist
- Check your depth — Each vehicle has a crush depth. Going even 2m below destroys it instantly.
- Scan for threats — Use the Seamoth sonar upgrade to detect predators before they detect you.
- Mark with beacons — Drop a beacon at every biome entrance, base location, and wreck for navigation.
- Check resources — Scan for specific resources using the Scanner Room before diving.
- Bring power cells — A Seamoth uses 1 power cell per 15 minutes of active driving. Carry spares.
- Watch your oxygen — At 500m+, a standard O2 tank gives only 45 seconds. Upgrade to High Capacity before deep dives.
- Stick to cave roofs — In caves, navigating by the roof is easier than the floor. Light glows from above.
- Listen for roars — Each leviathan has a unique roar audible from 300m away. Learn the sounds.
- Plan exit routes — Know which entrance you'll use to leave before you enter. Getting lost in deep biomes without oxygen is fatal.
- Build outposts — Place a small base (1 room + 1 solar panel + 1 fabricator) at key biome intersections for emergency refueling.