Subnautica Walkthrough — Start to Endgame

Subnautica drops you alone on an alien ocean planet after your spaceship crashes, and what follows is one of the best survival games ever made. The game masterfully creates fear through depth — the deeper you dive, the darker it gets, the more dangerous the creatures become, and the more incredible the discoveries are. There are no guns (by deliberate design choice), forcing you to rely on evasion, tools, and vehicles to survive. The story unfolds organically through radio signals, data logs, and environmental storytelling, guiding you ever deeper toward answers about the planet, the alien disease you've contracted, and how to escape. Nearly every player remembers their first encounter with a Reaper Leviathan.

This walkthrough takes you from your first session to endgame content. Each phase has specific goals, priorities, and milestones. Follow this path to avoid common traps that stall most players.

Quick Progression Summary

Phase 1: Getting Started — Safe Shallows

The starting biome directly around your lifepod. Shallow water (0-40m) with abundant basic resources and harmless fish. This is where you build your first base, craft basic tools, and learn game mechanics. No predators except the occasional Gasopod at the edges.

Level/Difficulty: 0-40m depth Key Rewards: Basic materials (Titanium, Quartz, Copper), Table Coral, Acid Mushrooms, first base location

What to Do in Safe Shallows

1. Learn base building. Bases are constructed from modular pieces: I-compartments, T-compartments, multipurpose rooms, and glass observatories. Spend your first session getting comfortable with this.
2. Pick PRAWN Miner as your starting build. It's the most forgiving option.
3. The radio in your lifepod broadcasts messages on a timer — always respond to radio calls because they mark key locations on your map and drive the story forward.
4. Acquire your first equipment upgrade — Stasis Rifle or whatever's available.
5. Clear all main content before moving on.

Phase 1 Checklist

• Understand base building fundamentals
• PRAWN Miner selected and functional
• Safe Shallows main content cleared
• Ready for Kelp Forest

Phase 2: Early Game — Kelp Forest

Dense kelp forests surrounding the Safe Shallows with Stalkers (aggressive shark-like predators) that collect metal salvage. Stalkers drop their teeth when biting metal — Stalker Teeth are needed for Enameled Glass. The Kelp Forest has Creepvine (silicone rubber) and Silver Ore in sandstone outcrops.

Level/Difficulty: 40-100m depth Key Rewards: Creepvine, Silver Ore, Stalker Teeth, Seamoth fragments

What to Do in Kelp Forest

1. Work on vehicle crafting. Three vehicles unlock progression: the Seamoth (fast, 200-900m depth), the PRAWN Suit (walking mech, 900-1700m, drill arms for mining), and the Cyclops (massive submarine, mobile base, 500-1700m). This system becomes critical from here on.
2. Farm for Stasis Rifle if you haven't already. It's the key upgrade for this phase.
3. Drop Beacons at every important location — wreck sites, resource deposits, cave entrances, and base locations. Beacons are cheap to craft and prevent you from losing discovered locations.
4. Complete all objectives before pushing to Lost River.
5. Consider whether Seamoth Explorer might suit your playstyle better than PRAWN Miner.

Phase 2 Checklist

• vehicle crafting integrated into gameplay
• Stasis Rifle acquired
• Kelp Forest fully cleared
• Ready for Lost River

Phase 3: Mid Game — Lost River

A massive underground cave system at 500-900m with brine rivers (acidic green fluid that damages you) and the Ghost Leviathan juvenile. Contains the Disease Research Facility — a major story location with alien data. The Lost River is the gateway to the deeper Inactive Lava Zone.

Level/Difficulty: 500-900m depth Key Rewards: Nickel Ore, Disease Research Facility, Precursor data, Ghost Leviathan encounter

What to Do in Lost River

1. Master depth progression. The ocean is layered by depth: 0-100m is safe and bright, 100-300m introduces moderate predators, 300-900m has dangerous biomes and leviathans, and 900-1700m contains the most dangerous creatures and the story's climax. This unlocks a new layer of gameplay.
2. Start working toward Survival Knife. It's the best equipment and becomes accessible around now.
3. The Scanner Room with 4 Range Upgrades covers a 500m radius and finds any resource type. Build one in a central location to eliminate all resource-searching frustration.
4. This area is the main skill check. If you can clear it, you're ready for late game.
5. Start investing in scanner room for the tactical depth you'll need going forward.

Phase 3 Checklist

• depth progression mastered
• Survival Knife acquired or in progress
• Lost River fully cleared
• Ready for Lava Zone

Phase 4: Late Game — Lava Zone

The deepest accessible biome at 1200-1700m, filled with volcanic activity, Sea Dragon Leviathans, and the Primary Containment Facility (where the Sea Emperor lives). The thermal environment heats your PRAWN suit, and the Sea Dragon Leviathan shoots fireballs. This is where the story concludes.

Level/Difficulty: 1200-1700m depth Key Rewards: Kyanite, Primary Containment Facility, Sea Emperor, Hatching Enzymes (cure), Ion Power Cell blueprints

What to Do in Lava Zone

1. Finalize your build. You should be running Seamoth Explorer or PRAWN Miner with optimized gear.
2. Survival Knife should be your primary. If you don't have it yet, prioritize getting it.
3. The Cyclops in Silent Running mode is nearly undetectable by Leviathans. Keep it in slow speed and silent running when traversing dangerous areas like the Lost River or Lava Zone.
4. alien research optimization starts here. Small improvements compound into massive advantages.
5. Farm this area for the resources needed to push into Crash Zone.

Phase 4 Checklist

• Build fully optimized
• Survival Knife upgraded to max
• Lava Zone fully cleared
• Ready for Crash Zone

Phase 5: Endgame — Crash Zone

The wreckage of the Aurora spaceship with heavy radiation requiring a Radiation Suit. The Crash Zone is patrolled by multiple Reaper Leviathans — the game's most famous terror. Inside the Aurora wreck you find the PRAWN Suit blueprints, Seamoth depth modules, and the nuclear reactor. Essential to explore but terrifying.

Level/Difficulty: 0-300m depth (heavy radiation) Key Rewards: PRAWN Suit blueprints, Cyclops blueprints, Seamoth depth modules, Nuclear Reactor, Laser Cutter (needed to access rooms)

What to Do in Crash Zone

1. Crash Zone tests everything. Come prepared with your best build and gear.
2. Reaper Leviathans can be avoided by hugging the ocean floor and moving slowly. They detect motion and sound — if you hear a roar, stop moving and they may lose interest.
3. The endgame loop: run Crash Zone, optimize gear, push harder content.
4. Experiment with Speedrunner for a fresh take once you've mastered the standard builds.
5. This is where alien research mastery separates good players from great ones.

Phase 5 Checklist

• Endgame content on farm
• Best-in-slot gear acquired
• Crash Zone fully cleared
• Ready for challenge content

Common Progression Mistakes

• Going to the Aurora wreck before crafting a Radiation Suit — radiation kills you slowly and you'll die before reaching the useful areas inside the ship.
• Building your base too deep or in a biome with aggressive predators — the Safe Shallows and Grassy Plateaus are the best base locations for a first playthrough.
• Ignoring the radio messages and trying to explore randomly — the radio provides critical story breadcrumbs and map markers that guide natural progression.
• Trying to fight Leviathans with the knife — the game is designed around avoidance, not combat. A Reaper Leviathan has 5000 HP and your knife does 20 damage.
• Not building a Seamoth as soon as possible — swimming everywhere wastes oxygen and puts you at constant predator risk. The Seamoth should be your first major crafting goal.

Key Tips for Smooth Progression

1. The radio in your lifepod broadcasts messages on a timer — always respond to radio calls because they mark key locations on your map and drive the story forward.
2. Drop Beacons at every important location — wreck sites, resource deposits, cave entrances, and base locations. Beacons are cheap to craft and prevent you from losing discovered locations.
3. The Scanner Room with 4 Range Upgrades covers a 500m radius and finds any resource type. Build one in a central location to eliminate all resource-searching frustration.
4. The Cyclops in Silent Running mode is nearly undetectable by Leviathans. Keep it in slow speed and silent running when traversing dangerous areas like the Lost River or Lava Zone.
5. Reaper Leviathans can be avoided by hugging the ocean floor and moving slowly. They detect motion and sound — if you hear a roar, stop moving and they may lose interest.

For detailed build optimization, see Subnautica builds. For quick wins, check tips & tricks.