Subnautica 2 Secrets Guide: Hidden Caches, Rare Blueprints & Collectible Locations

Subnautica 2 doesn't have a collectibles menu. It doesn't track what you've found. You either stumble across things or you miss them forever. I've been mapping hidden locations since Early Access launched and I'm fairly confident I've found most of what's currently in the game.

Some of this will probably change with updates. Locations might shift. Items might get added. But as of June 2026, here's what's out there.

The Cicada Colonist Recordings

Scattered across the map are data logs left by the original Cicada colonists. These aren't marked on your HUD. NoA doesn't mention them. You find them by exploring wrecks thoroughly.

I've located six so far. Each one is a short audio log from a different colonist during the 25-year period between the crash and your printing. They paint a grim picture of what happened. The Proteavirus spreading through the colony. People losing their minds. The decision to stop printing new people. The last recording is from someone who chose to walk into the ocean rather than let the virus take them.

Finding these logs doesn't give you items or blueprints. It gives you context. The story is much darker than NoA's cheery mission briefings suggest. If you care about the narrative at all, hunt these down.

Locations I've confirmed: one in the Cicada's engine section at 200 meters north of the Shallows, one in a small outpost in the Vine Tangle at 150 meters, one in the Reef Shelf near a giant coral formation, one in the upper Fungal Basin inside a sealed laboratory module, one in the Trench at 400 meters inside a cave behind a waterfall current, and one in a deep outpost past 600 meters that requires the Deep Tadpole chassis to reach.

The Alien Data Vault

The Axum left technology behind. Most of it is story-critical and you'll find it naturally. But there's one structure that's entirely optional.

At roughly 550 meters in the lower Fungal Basin, there's a sealed Axum vault built into a rock wall. You need an Ion Cube to open it. The nearest Ion Cube is in the Trench, inside a small alien structure at 450 meters. It's behind a force field that opens when you approach with the correct Biomod equipped. I'm not sure which Biomod specifically. I had three equipped when I tried and something worked.

Inside the vault: a data terminal with Axum lore, a blueprint for a Biomod expansion chip (the only guaranteed one I've found), and a decorative Axum artifact that you can place in your base. The expansion chip is the real prize. It gives you a third Biomod slot. I've only found one other chip in 50 hours and it was a random drop, not a fixed spawn.

Time Capsules and Community Content

Subnautica 2 has a time capsule system similar to the first game. Players can leave capsules with items and messages. These get approved by the developers and seeded into other players' worlds.

I've found three so far. One contained a fully upgraded knife and a message that just said "don't eat the yellow ones." Good advice. Another had a picture of someone's cat next to their monitor and a Cuddlefish equivalent egg. The third had Ion Batteries and a note thanking the devs for the co-op feature.

Time capsules spawn randomly. There's no fixed location. The more you explore, the more likely you are to find one. The Cuddlefish equivalent is called a Glowfin on Proteus. It's a small bioluminescent companion that follows you around the Shallows. No gameplay benefit. Pure dopamine.

Rare Blueprint Locations

Some blueprints only spawn in one place. Not one biome. One specific wreck or structure. Here are the ones I've confirmed.

The Electric Discharge Biomod blueprint is inside a wreck at 350 meters in the Trench. Look for a sealed laboratory module with a broken window. You can swim through the window without a Laser Cutter. The blueprint is on a desk inside.

The Thermal Reactor module for the Tadpole comes from scanning a piece of Axum technology in the lower Fungal Basin. It's near the vault I mentioned earlier. The piece is embedded in a heat vent. You'll take damage getting close enough to scan it. Bring a Repair Tool and medkits.

The Deep chassis for the Tadpole is in a wreck at 500 meters in the Trench. You need the Laser Cutter to access the main compartment. The fragments are on a shelf above a flooded corridor. I missed them twice because I didn't look up.

The Easter Egg Void Portal

At the very edge of the map, past 800 meters in the Void, there's a structure. I found it by accident while running from an Entity manifestation. It's a small Axum portal platform. Inactive. No obvious way to power it.

The community is still trying to figure out what it does. Some people think it's cut content. Others think it requires an item that hasn't been added yet. A few claim it activates during specific in-game conditions but I haven't seen any proof.

If you want to see it yourself, go to the southeastern edge of the map. Descend past 800 meters. Follow the temperature drop. The platform is on a small rocky outcropping just before the seafloor drops into the true abyss. Bring the Deep chassis and at least four spare power cells. The trip back is long.

One thing I'll add: I've been there twice. Once solo and once in co-op. In co-op the portal platform had an additional pillar that wasn't there in solo. Could be a rendering bug. Could be something else. Unknown Worlds hasn't commented on it.

What I Haven't Found

There are almost certainly things I've missed. The map is large and the game is Early Access. I've seen references in datamined files to a creature called "the Song" that might be in the deepest Void. No one has posted credible footage of it. The Axum main storyline's final area isn't accessible yet. There are references to a "Final Archive" that probably won't be added until closer to 1.0.

The bottom line with secrets in Early Access is that some of them genuinely aren't finish yet. If you've searched everywhere and can't find something you've heard about, it might not be in the game. Check the Unknown Worlds development blog before spending hours hunting for content that doesn't exist.