Barotrauma’s world is divided into a series of biomes beneath Europa’s frozen surface. Each biome increases in depth, complexity, and difficulty, offering unique challenges, hazards, monsters, and visual environments. As your submarine ventures further, you’ll need to adapt your tactics, upgrade your gear, and prepare for increasingly hostile terrain. This guide breaks down every biome in the single-player campaign, detailing what to expect and how to survive.

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1. Cold Caverns

Difficulty Range: 0–15
Distance Between Stations: 700–1500 meters
Key Features: Ice Spires, basic caves, beginner-friendly zones

The Cold Caverns are the starting biome and the safest. Visually bleak with dark gray tones, they feature scattered ice spires that protrude from floors and ceilings. Crashing into them causes hull breaches and flooding.

There are four level types in this biome:

• Beginner: Very short (700m) missions
• Open Space: Simple wide levels (~1500m)
• Maze-like: More obstacles, tighter passages (~1300m)
• Transition: Occur at the biome’s end, includes potential wrecks

Tips:

• Shoot ice spires before impact
• Avoid narrow side tunnels unless prepared for combat

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2. Europan Ridge

Difficulty Range: 15–35
Distance Between Stations: 1100–1300 meters
Key Features: Icebergs, ballast flora, Abyssal vents, Thalamus chance (10%)

Replacing spires with icebergs, this biome ups the ante. Icebergs are tougher and require more ammo to destroy. Three caves and one wreck may spawn per level, and there’s a 60% chance to discover an Abyssal Vent, introducing powerful deep-sea monsters.

New hazard: Ballast Flora, visible as shimmering clouds on sonar. If entered while descending, flora can attach to pumps, dealing continuous burning damage.

Visuals: More vibrant rocks and small plant life inside and outside caves.

Tips:

• Avoid ballast flora clouds entirely
• Be prepared for more complex missions, like wreck salvages and artifact recovery

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3. Theaphotic Plateau

Difficulty Range: 35–50
Distance Between Stations: ~1900 meters
Key Features: Alien ruins begin to spawn, increased Thalamus chance (30%)

This biome has a maze-like layout and is the first where crush depth becomes a consistent hazard. Hull upgrades are mandatory to continue progression.

Visuals: Thick aquatic flora resembling coral forests dominates this area, with caves becoming denser and more dangerous.

Tips:

• Always upgrade hulls before entering
• Watch for early alien ruins with traps and guardian monsters

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4. The Great Sea

Difficulty Range: 50–65
Distance Between Stations: ~2700 meters
Key Features: Icebergs (up to 20), Piezo Crystals, Thalamus chance (40%), high pressure zones

The Great Sea increases iceberg frequency and adds the Piezo Crystal hazard. These purple crystals, when within 30 meters of your submarine, zap your electrical systems with 500 kW of power, breaking junction boxes or setting fires. You can shoot them, but beware—they explode:

• 2000 structural damage
• 300 burn & explosive damage
• 10m blast radius
• 20s stun duration

Visuals: Returns to icy gray tones with crystal elements added to walls and backgrounds.

Tips:

• Stay 30m+ away from Piezo Crystals or destroy them safely
• Upgrade diving suits—depths start at 4000m and exceed standard suit thresholds

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5. Hydrothermal Wastes

Difficulty Range: 65–80
Distance Between Stations: ~2700 meters
Key Features: Volcanic visuals, double swarm spawns, Thalamus chance (50%), sonar flora

This is the most dangerous biome in the game. Visually striking with glowing volcanic rocks and red-hued water, you’ll encounter:

• Hammerhead swarms
• Giant Spineling groups
• Frequent Thalamus wrecks

Hazard highlight: Sonar Flora. This purple plant disables your sonar, masking threats and the map layout. Only solution: move your sub away.

Tips:

• Bring top-tier armor, weapons, and repair supplies
• Prepare for stacked monster spawns
• Be extra cautious when sonar is jammed—Black Molochs may be nearby

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Key Takeaways by Biome

Biome	Avg. Distance	Difficulty	Unique Hazards	Notes
Cold Caverns	700–1500m	0–15	Ice Spires	Best for new players
Europan Ridge	1100–1300m	15–35	Icebergs, Ballast Flora, Abyss Vents	Introduces Thalamus and cave mobs
Theaphotic Plateau	~1900m	35–50	Crush Depth, Alien Ruins	Hull upgrades become necessary
Great Sea	~2700m	50–65	Piezo Crystals, Deep Zones	Suit upgrades required
Hydrothermal Wastes	~2700m	65–80	Sonar Flora, Swarm Doubles	Final biome, extremely hostile

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Final Notes

Biome progression in Barotrauma is not just about surviving harder enemies—it’s about navigating increasingly complex environments, adapting to new threats, and pushing your submarine’s limits. From silent ice spires to chaotic volcanic vents, each stage of the campaign offers fresh opportunities and new dangers.

Plan your routes, upgrade your gear, and most importantly—respect the ocean.

Until next time, safe diving.