The water went black and the Tadpole stuttered before I could even blink. I sat there, breath held, knowing a single upgrade would change everything. One scan later, the route through the ruins felt obvious.
I’ve been mapping these modules since Subnautica 2 hit Steam and Discord lit up with tips. You’ll get straight directions here — I’ll tell you where to go, what to expect, and which upgrades are worth your time. Follow my route and you’ll shave hours off wandering the map.
How do I find all Tadpole upgrades?
Start at your Lifepod, set a compass bearing from the Alien Ruins Research Outpost, and follow the sequence I use — it strings locations together so you don’t backtrack. Use your scanner, keep the Tadpole docked when necessary, and consult the PDA markers or a Subnautica Discord map if you lose your way.
Scout Ray Chassis location
I often pause at the entrance to the Tadpole Pens and watch the warm water steam light the rock. The Scout Ray chassis is the one exception to the Outpost-centric pattern: head to the Tadpole Pens in the warm biome, go straight through the facility, and the Scout Ray is sitting in the Moonpool — scan it and it’s yours.
Install this first if you can — the Scout Ray chassis gives the Tadpole a massive speed boost, like slapping a turbo into a bike. That speed pays off when you’re hitting the rest of the Outpost waypoints.
Engine Efficiency
At eye level with the Outpost’s corridor lights you’ll notice the hum of functioning generators. From your Lifepod, head east to the Alien Ruins Research Outpost at roughly 1300m, go inside and turn right — the Engine Efficiency module sits in that area and is a quick scan.
Strike Armor
The salt on the hull near the outpost always flakes first where currents bite the rock. From the Research Outpost, set a heading between 195 and 210 degrees and descend gradually to about 190m. At around 60m from the outpost you’ll spot a platform holding the Strike Armor module — scan it while keeping an eye out for patrol creatures.
Where is the Scout Ray chassis?
It’s in the Tadpole Pens moonpool, inside the warm biome. If you’ve been tracking markers on Steam or Reddit maps, that location is the only one outside the Alien Ruins cluster.
Cavitation Muffler upgrade location
The Power Center looks like a cathedral of metal from a few hundred meters out. Return to the front of the Outpost, aim roughly 75 degrees east, and push to deeper water until you find the domed structure in the image — pass the visible arc and pillar, then keep left as the seafloor turns into a cliff.
Follow the colored alien plants and watch your depth — at about 370m you’ll hit a platform perched at the cliff edge near the early-access boundary. That’s where the Cavitation Muffler sits; grab it and head back to the Outpost. The muffler will quiet the Tadpole’s noise signature, like putting a hand over a barking engine.
Photovoltaic Charger upgrade location
The Alterra wrecks always draw a scatter of debris and metal shards at 120m depth. From the Outpost head to 120 degrees and use the Blackbox – Iso marker — you’ll find an Alterra starship wreck. Park the Tadpole, enter through the left door, repair the broken door you meet, then take the left corridor and the next left to reach the room with the ISO. The Photovoltaic Charger module sits diagonally opposite the dining table.
Depth Module Mk. I upgrade location
The seabed around Blackbox Ruby 2 is strewn with wreck pieces and a lonely Tadpole hull. From the Outpost aim 165 degrees, follow the Blackbox – Ruby 2 marker, and reach the bottom layer of the site. You can squeeze through broken rocks (leave your Tadpole) and recover Ruby 2’s black box; the Depth Module Mk. I sits next to a broken Tadpole hull.
Haul Chassis upgrade locations
Blueprint fragments for the Haul Chassis are scattered like breadcrumbs near wrecks and root systems. You need to scan three fragments: the first is beside the Depth Module Mk. I site. Then return to the Research Outpost and head between east and 105 degrees — pass the Power Center dome and at around 200m depth you’ll find another Alterra wreck with the second fragment on a platform to the left.
For the final fragment, head past the Angel Comb root structure (a handy reference used across Subnautica threads on Reddit and Discord). Follow the root until you reach an acidic pool; inside the pool room, look left past the alien structures and you’ll find the last chassis piece. Scan all three to learn the Haul Chassis blueprint and equip it.
Once scanned, the Tadpole can equip the Haul Chassis and start hauling salvage like a pocket-sized freight liner. Many players on Steam and forums recommend Haul last, but if you plan to farm wrecks it’s worth grabbing early.
How do I get the Haul Chassis?
Scan three fragments: one near Depth Module Mk. I, one at the 200m Alterra wreck, and the last inside the acidic pool past the Angel Comb roots. Use your scanner and mark each fragment in the PDA so you don’t circle back blind.
If you want tighter route planning, overlay your PDA markers with a community map — Moyens I/O’s screenshots and Reddit user maps saved me a dozen hours. Running Subnautica 2 on a Steam Deck or PC with a mapped compass helps keep bearings when the light goes green and the ocean starts to close in.
Which module would you grab first if you could only take one into the ruins — speed, silence, or hauling power?