The Tadpole is the first proper submersible you'll build in Subnautica 2, and the Half Round Room is the cleanest early base upgrade for getting a panoramic view of Proteus. Both are gated behind blueprints you have to find in the wild, and both sit close enough to your starting Lifepod that you can grab them within the first few play sessions if you know where to swim.
Tadpole blueprint: How the unlock works
The Tadpole blueprint isn't a single pickup. You unlock it by scanning three Tadpole Fragments with your Scanner, and there are nine fragments seeded across the early biomes around Proteus. You only need three, so pick whichever cluster is closest and safest for your current gear.
If you're playing Creative Mode, the blueprint is already in your fabricator. Survival Mode players need the Scanner (auto-unlocked at the start of the game) and ideally the Habitat Builder before the Tadpole becomes useful, since you'll need a Moonpool to dock it.
Closest Tadpole Fragment locations
The fastest unlock route uses fragments within 300 meters of the Lifepod. The east-northeast cluster rides a natural current, so you can drift between the first two without burning oxygen swimming back.
| Fragment | Direction from Lifepod | Distance | Landmark |
|---|---|---|---|
| #1 | East-northeast | 280 m | Canyon current, next to a cargo container with a Hydroelectric Turbine |
| #2 | East-northeast | 380 m | Cicada Wreck (Lander Garage), beside a scannable Bioreactor |
| #3 | North-northeast | 420 m | Plateau near a crashed Alterra ship, alongside the Ruby blackbox |
| #4 | North-northeast | 480 m | Rocky crags near the Behemoth Finger-Legged Jelly |
| #5 | North-northwest | 430 m | Back of the Old Habitat |
| #6 | South-southwest | 160 m | Cliffside ridge near a Great Jaw organism |
| #7 | South-southwest | 300 m | Inside a Colonist Bunker |
| #8 | East | 515 m | Zezuran Desert (requires Angel Comb Adaptation for heat) |
| #9 | Story location | — | Tadpole Pens (visit after you've already built the vehicle) |
The cheapest path is fragments #1 and #6 plus one of #2 or #7. That keeps you above 200 meters depth and away from the heat-locked Zezuran Desert.
Building the Tadpole after unlocking
Scanning three fragments unlocks the vehicle blueprint, but the Tadpole only spawns from a Vehicle Fabricator attached to a Moonpool. You'll need to build the supporting structures first, all of which require the Habitat Builder and a reasonably expanded base.
| Structure | Resources |
|---|---|
| Tadpole (vehicle) | 2x Titanium Ingot, 1x Glass, 1x System Chip, 1x Power Cell |
| Moonpool | 5x Titanium |
| Tadpole Dock | 2x Titanium Ingot, 1x Silver Ingot, 2x Copper Wire |
| Vehicle Fabricator | 2x Titanium Ingot, 1x Copper Ingot, 2x Glass |
A single Room is usually too tight to fit the Moonpool plus both fabrication attachments. Stack two Rooms in the same footprint to widen the interior before placing the Moonpool, then attach the Tadpole Dock and Vehicle Fabricator to its sides.
Half Round Room blueprint location
The Half Round Room is a structural variant with a panoramic window on one side, locked behind its own data card hidden in a wreck east of the Lifepod. You need the Habitat Builder before the blueprint becomes useful, so unlock that first if you haven't already.
Step 1: From the Lifepod, swim due east for roughly 500 meters until you reach a large wrecked structure on the seabed.
Step 2: Locate the hole in the wreck and drop through it. The lower section runs hot, so the Angel Comb (Heat Tolerance) adaptation is strongly recommended. Without it, you can still make the run, but you need to move quickly and bring extra oxygen.
Step 3: Once inside, enter the first passage and turn left immediately. Look for an opening cut into the left wall of the corridor.
Step 4: Swim through that opening. The Half Round Room data card sits at the back of the side room. Grab it and the blueprint is added to your Habitat Builder.
Verifying both unlocks
For the Tadpole, open the Vehicle Fabricator menu after scanning your third fragment. The Tadpole entry should appear as craftable (assuming you have the materials). If it still shows as locked, you've only scanned two fragments or one of your scans didn't register, which usually means the Scanner ran out of progress before completing.
For the Half Round Room, open the Habitat Builder and check the Rooms category. The new variant appears alongside the standard Room with a half-circle silhouette and a window icon. If it's missing, you picked up something else in the side room and need to return to scan the actual data card.
With both blueprints unlocked, you have what you need to expand from a corridor-only base into something that can actually house a submersible, and to start building deeper outposts with proper viewing windows out into Proteus's biomes.