Subnautica 2 All Biomes Guide: Depths, Resources & Dangers

How Biomes Work in Subnautica 2

Planet Zezura’s ocean is divided into distinct biomes, each with its own ecosystem, resource profile, and danger level. Unlike a traditional game map with clear borders, biomes blend into each other through transition zones. You’ll notice the water color shifting, the flora changing, and new creatures appearing as you cross from one zone to the next.

There’s no map. Navigation relies on your Compass, Beacons, and the XYZ coordinates visible in the pause menu. Learning to recognize biomes by their visual character is a survival skill, not just trivia. When the kelp disappears and the water turns murky, you should know what that means before something with teeth tells you.

Subnautica 2 features 51 creature types across all biomes, including 5 or more Leviathan-class species. The Leviathans are not optional mini-bosses. They are territorial predators that will kill you, destroy your vehicle, or both. Knowing which biomes house Leviathans is the difference between exploration and a loading screen.

Kelp Forest

Depth range: 0-80 meters Danger level: Low Best for: Early game gathering, Scanner targets, Angel Comb hunting

The Kelp Forest is your starting biome and the safest place on Zezura. Towering kelp stalks grow from the seafloor to the surface, creating vertical columns of vegetation that provide cover and landmark navigation.

Key Resources

• Titanium — from limestone outcrops on the seafloor, plentiful
• Copper — also from limestone outcrops, less common than Titanium
• Quartz — translucent crystals near rock formations
• Angel Comb — the biological sample that cures Digestive Incompatibility
• Kelp fibers — harvestable from the stalks, used in basic crafting

Creatures

Most fauna here is passive or defensive. Small fish are scannable and, once you cure your Digestion, edible. The few aggressive species are small and easily avoided or dispatched with a Survival Knife.

No Leviathans spawn in the Kelp Forest. This is your safe zone.

Notable Locations

• Lifepod (spawn point) — surface level
• Welcome Center — 85-90m SE of Lifepod, shallow depth
• Camp One — 240m NE (heading 60), Kelp Forest edge
• Old Habitat — 350m N, near the Kelp Forest boundary

How to Navigate

The kelp stalks create natural corridors. Use them as landmarks. If you can see kelp in every direction, you’re still in the safe zone. When the kelp thins out and the seafloor drops away, you’re approaching a transition.

Coral Gardens

Depth range: 60-200 meters Danger level: Medium Best for: Mid-game resources, Tadpole fragments, DNA Modification samples

The Coral Gardens sit below and beyond the Kelp Forest. Massive coral structures dominate the landscape — branching formations in reds, oranges, and purples that create a visually striking but more dangerous environment.

Key Resources

• Advanced minerals — ores needed for mid-tier crafting and electronics
• Coral samples — used in DNA Modification research
• Tadpole fragments — vehicle parts scattered in debris fields
• Biological samples — various species drop materials for the Bio Lab

Creatures

This is where things get aggressive. Predatory fauna patrols the Coral Gardens, and they’re faster and harder to dodge than anything in the Kelp Forest. Bring a Survival Knife at minimum. A Tadpole vehicle is strongly recommended.

Some mid-tier Leviathan species may patrol the deeper edges of this biome. Stay alert and don’t linger in open water without cover.

Getting There

Swim outward from the Kelp Forest in any direction except straight up. The transition happens gradually — you’ll see the kelp thin out and coral structures start appearing. Compass heading matters here. Mark your entry point with a Beacon so you can find your way back.

The Coral Gardens are where Wander’s Blackbox (the 5th in the story sequence) is located.

Thermal Vents

Depth range: 150-400+ meters Danger level: High Best for: Thermal power, rare minerals, deep-game resources

Thermal Vents are exactly what they sound like — volcanic fissures on the ocean floor that spew superheated water and mineral-rich plumes. The water here is hot enough to damage you without the Heat Tolerance adaptation.

Key Resources

• Rare ores — minerals that don’t spawn in shallower biomes
• Thermal energy — Thermal Generators produce 16 energy per second near vents, the highest output of any power source
• Heat-resistant biological samples — for advanced DNA Modifications

Environmental Hazards

Temperature damage. Without the Heat Tolerance adaptation (obtained through DNA Modification), swimming near active vents will steadily drain your health. The adaptation doesn’t make you immune — it raises your tolerance threshold. Prolonged exposure still hurts.

Low visibility. Mineral plumes and thermal distortion reduce visibility significantly. Your Flashlight is mandatory, and even then, navigation is tricky.

Pressure. The depth means your oxygen supply drains faster. An upgraded tank and a vehicle are practically required.

Creatures

Deep-water predators are bigger, tougher, and more aggressive. At least one Leviathan species calls the Thermal Vents home. You won’t mistake it for background scenery.

Getting There

You need to go deep. The Kelp Forest floor drops away into transitional slopes. Follow the terrain downward, ideally in a Tadpole. Mark the path with Beacons every 100 meters or so. Getting lost at 300 meters with low oxygen and no landmarks is how you learn to save more often.

Base Building Near Vents

Thermal Vents are the best location for a deep-water base. A single Thermal Generator outputs 16 energy per second — enough to power a fully equipped station. Build outside the direct damage radius of the vents but close enough for the generator to draw heat. Test placement before committing resources.

Alien Ruins

Depth range: 100-250 meters Danger level: Medium-High Best for: Lore, advanced technology scans, story progression

The Alien Ruins are structures built by a non-human civilization, long abandoned. They look nothing like anything else on Zezura — geometric forms, unfamiliar materials, and technology that your Scanner can partially decode.

Key Resources

• Alien data logs — story and lore entries that expand the narrative
• Advanced technology fragments — scannable objects that unlock late-game blueprints
• Unique biological samples — species found only in this biome
• Ion-based materials — rare crafting components for high-end gear

Creatures

The Ruins have their own ecosystem. Some species seem adapted specifically to the artificial structures. Aggression levels vary — some are territorial around specific ruins, others patrol more broadly.

Story Significance

Iso’s Blackbox — the 7th and final Blackbox of Chapter 1 — is located in the Alien Ruins. This entire area is narrative-critical. Scan every alien object you find. The data logs here set up the overarching plot for the remaining 9 chapters.

Getting There

The Alien Ruins are a mid-depth biome, but reaching them requires crossing through more dangerous territory. A Tadpole vehicle and upgraded oxygen are strongly recommended. Follow the story signals — once you’ve collected Blackboxes 1-6, the game directs you here.

The Void

Depth range: Variable, effectively bottomless Danger level: Extreme Best for: Nothing. Avoid it.

The Void is the edge of the playable map. Swim far enough in any direction and the biomes stop. The water goes dark. The seafloor drops away. And the Leviathans that live here are not the kind that let you swim away.

What’s Out There

Ghost Leviathans (or their Zezura equivalents). The Void serves the same function it did in the original Subnautica — it’s a boundary enforcer. The creatures here are aggressive, powerful, and will chase you relentlessly. There are no resources worth collecting. There is nothing to scan that justifies the risk.

How to Know You’re Approaching It

• The water gets dark fast, even near the surface
• Biome transition indicators disappear
• Your Compass readings stop matching any known landmark
• You hear things

What to Do

Turn around. If a Leviathan aggros on you, sprint toward the nearest biome boundary. They typically don’t follow you into inhabited biomes. If you’re in a Tadpole, full speed toward known coordinates. If you’re swimming, accept that the next 30 seconds will be stressful.

Biome Tier List for Base Building

Not all biomes are equal for setting up a base. Here’s how they rank:

Biome	Power Options	Safety	Resource Access	Verdict
Kelp Forest	Solar (1-8 E/sec)	Safe	Basic materials	Best starter base
Coral Gardens	Solar + Hydroelectric (12 E/sec)	Moderate	Mid-tier materials	Good mid-game hub
Thermal Vents	Thermal (16 E/sec)	Dangerous	Rare materials	Best deep base, high risk
Alien Ruins	Solar + limited options	Risky	Unique tech	Exploration outpost only
The Void	None practical	Fatal	Nothing	Never build here

Exploration Gear by Biome

Biome	Minimum Gear	Recommended Gear
Kelp Forest	Scanner, Knife	Compass, Flashlight
Coral Gardens	Compass, Knife, upgraded O2 tank	Tadpole vehicle, Beacons
Thermal Vents	Tadpole, Heat Tolerance adaptation, Flashlight	Thermal suit, high-cap O2 tank
Alien Ruins	Tadpole, Scanner, upgraded O2 tank	Full loadout, Beacons
The Void	Don’t go	Seriously, don’t

General Biome Navigation Tips

Drop a Beacon at every biome transition. When you cross from Kelp Forest into Coral Gardens, place one. Name it something useful like “Coral Entry North.” You’ll be grateful when you’re low on oxygen and trying to find the way home.

The pause menu coordinates are your friend. Each biome occupies a rough coordinate range. After a few hours, you’ll start recognizing that certain X and Z values mean Kelp Forest, while others mean Coral Gardens. Keep a notepad handy.

Sound design matters more than you’d expect. Each biome has a distinct audio profile. Learn what the Kelp Forest sounds like versus the Coral Gardens. When the ambient audio shifts, you’re crossing a boundary. If everything goes quiet and then you hear deep, low rumbling — you’ve gone too far.