Subnautica 2 Base Building Guide 2026: Best Locations, Power Management & Every Module

I built my first base in the Safe Shallows because the name said 'Safe.' It was. It was also 800 meters from every resource I needed and I spent half my playtime in transit. Base location is the single most impactful decision in Subnautica 2.

Best base locations ranked

S-Tier: Tree Cove (Lost River entrance) — No predators, thermal vents for unlimited power, direct access to Lost River resources AND surface biomes. Central hub location — equidistant to all endgame zones. Build your main base here. You'll never move it.

Grassy Plateaus (red grass, 100-200m) — Best early-mid game base. Central map location, tons of titanium/scrap metal, nearby kelp forest for creepvine. Reefbacks as ambient neighbors (zero threat). Depth is right below Seamoth crush depth without upgrades — build moonpool here, upgrade Seamoth, then go deeper.

A-Tier: Mushroom Forest (northwest) — Lithium everywhere, no predators, beautiful. Lithium is the most frustrating mid-game bottleneck. Build a scanner outpost here just for lithium mining. Sparse Reef (south) — Zero predators, tons of rubies and gel sacks. Perfect secondary scanner base. Nothing in this biome can hurt you. Grand Reef (300m) — Endgame materials (crystalline sulfur, nickel), close to Lost River entrance. Build once you have Prawn Suit.

B-Tier: Kelp Forest — Creepvine access for lubricant and silicone rubber. Too shallow for anything but a starter tube + fabricator. Jellyshroom Caves — Magnetite, shale outcrops. Beautiful but Crabsnakes will harass you constantly. Scanner outpost only.

C-Tier: Safe Shallows (starting area) — Outgrow it in 2 hours. Keep a tube here as a waypoint. Don't invest resources. Blood Kelp Zone — Warpers patrol here. Never build where Warpers can warp you out of your base.

F-Tier: Dunes, Crash Zone, Mountains — Reaper Leviathan territory. You know what a Reaper is. Don't build here.

Power grid: the math

Solar panels: 75 power/minute during day, 0 at night. Depth penalty: -10% per 100m below surface. At 200m: 60/min. At 400m: 45/min. Solar only viable above 200m. Best with battery storage (power cell charger banks store excess for night).

Thermal plant: 50-250 power/min based on vent temperature. 50°C = 50/min, 100°C+ = 250/min. Unlimited, no maintenance, works at any depth near vents. Build thermal plants with power transmitters to your base — transmitters extend range 100m per relay. This is the best power source endgame.

Bioreactor: 50 power/min per module. Fuel: gel sacks (best — 420 power per sack, farmable in exterior growbed), reginald fish (2nd best — 490 power per fish, breed in alien containment). Oculus fish (3rd — easy to catch). 4 gel sacks in a growbed = infinite bioreactor fuel.

Nuclear reactor: 250 power/min. One reactor rod = 20,000 power = ~3 hours real time. Requires uraninite (Lost River, Inactive Lava Zone). Best for large bases with water filtration (water filtration drains 50 power/min EACH). 4 rods = 12 hours of unlimited power.

Power priority: Thermal > Nuclear > Bioreactor > Solar. One thermal plant on a 100°C vent powers a small base forever. Two thermal plants = water filtration + moonpool charging + scanner room simultaneously.

Every habitat module explained

Essential: Multipurpose Room (main hub), Moonpool (vehicle docking + charging), Scanner Room (resource finding — build one at every outpost), Power Cell Charger (moonpool charges vehicles, charger does spare cells), Battery Charger (always have 4 spare batteries charging), Water Filtration Machine (free water + salt → cured food), Alien Containment (breed fish for bioreactor/food — 2 Reginalds breed to fill containment in 3 game days).

Nice to have: Observatory (glass dome for view — no gameplay function, build for fun), Growbed (exterior plant farming for gel sacks, deep shrooms, blood oil), Aquarium (small fish display, not functional — Alien Containment is functional).

Skip: Trash Can (just drop items outside), Counter (decoration, no storage), Single Bed (doesn't skip night, sleep is purely cosmetic).

Multi-base strategy: One main base (Tree Cove: crafting, storage, vehicle bay), 2-3 scanner outposts (Mushroom Forest for lithium, Sparse Reef for rubies/gel sacks, Lost River junction for endgame materials). Outposts need: Multipurpose Room + Scanner Room + Bioreactor + Power Cell Charger. 4 rooms total per outpost.

Reinforcement: Hull integrity drops 1.0 per window, 0.5 per reinforcement panel. 4 lithium + 2 titanium = 1 reinforcement panel (+7.0 hull integrity). Foundation adds +2.0 hull integrity. Bulkhead (hatch door) adds +3.0. Don't let hull go negative — your base will flood and you'll die.