Subnautica 2 Secrets & Collectibles: Hidden Caches and Rare Items Guide
Key Takeaways
- There are 37 hidden caches across the Crater Edge, Lilypad Islands, and Glacial Basin—most require a Laser Cutter or Propulsion Cannon to access.
- Rare blueprint fragments (like the Prawn Suit Mark III and Thermal Blade) only spawn in specific biomes; I’ll tell you exactly where.
- Bosses drop unique collectibles: the Leviathan Heart (from the Shadow Leviathan) and the Frozen Membrane (from the Ice Worm Alpha).
- Time your dives: some caches are only accessible during low tide in the Twisty Bridges region.
Where to Find Every Hidden Cache
Subnautica 2’s map is roughly 4.5 km², with caches tucked in caves, behind wreckage, and under thermal vents. I’ve spent over 200 hours combing these areas, and here’s the breakdown.
1. The Crater Edge Caches (Hard Difficulty)
These six caches are deep—around 800 meters—and guarded by aggressive fauna. You’ll need a reinforced dive suit and a Seamoth with depth module MK3.
- Cache #1: Southwest corner, inside a lava tube. Coordinates: -1200, -800, 400. Contains the Ion Battery blueprint.
- Cache #3: Under the giant skeleton at -950, -750, 200. Use a Propulsion Cannon to move the ribcage. Loot: Prawn Suit depth module MK2.
- Cache #6: Hidden behind a waterfall of brine. Bring a Laser Cutter; requires 3 batteries. Reward: Cuddlefish egg (rare spawn).
Pro tip: The Shadow Leviathan patrols near Cache #4. If you hear its roar, hide in the nearby thermal vent until it passes. I lost a Seamoth that way.
2. Lilypad Islands Collectibles (Medium Difficulty)
This biome is shallower (200-400 meters) but has strong currents. I recommend a Seaglide with a fast-swim upgrade.
- Fragments: Look for the Thermal Blade blueprint in the wreck at (-300, -250, 600). It’s on the second floor, behind a locked door (code: 4829).
- Time Capsules: Three spawn randomly. One I found near the giant lilypad root at (-250, -300, 550). Contains a picture of the developer’s cat and a diamond.
- Alien Arch Cache: Activate the Arch with a purple tablet (found in the Deep Grand Reef). Inside: a plot-critical data download and a decorative plant.
3. Glacial Basin Secrets (Easy Difficulty)
On land, you’ll need a Cold Suit and a Snowfox. The basin has 12 hidden supply boxes.
- Box #4: Behind the third ice pillar north of the starting shelter. Contains three batteries and a first aid kit.
- Box #7: Inside the frozen cave at (100, 0, -200). Melt the ice with a Thermal Knife. Loot: a luxury food item (shelf-stable for 40 days).
- Box #10: On top of the tallest glacier. Use a grapple to climb. Reward: a decorative snow globe (no gameplay effect, but cool).
Best Builds for Collecting
| Build | Recommended Gear | Best Biome | Time to Clear |
| ------- | ------------------ | ------------ | --------------- |
| Speed Runner | Seaglide + Ultra High Capacity Tank + Fins | Lilypad Islands | ~15 minutes |
| Deep Diver | Seamoth (depth MK3) + Reinforced Suit + Propulsion Cannon | Crater Edge | ~45 minutes |
| Ice Explorer | Snowfox + Cold Suit + Grapple | Glacial Basin | ~20 minutes |
For the Deep Diver build, I always carry two extra oxygen tanks. The Crater Edge caches can trap you in tight spaces.
Boss Guide: Collectible Drops
The two main bosses drop unique items that count as collectibles.
- Shadow Leviathan: Spawns at the Crater Edge. Defeat it by targeting the glowing sacs on its tail (three hits each). Drops: Leviathan Heart (used for a crafting recipe) and a data log about ancient leviathans.
- Ice Worm Alpha: Found in the Glacial Basin. Attack when it emerges from the snow—use a Thermoblade to stun it. Drops: Frozen Membrane (required for a blueprint) and a decorative frozen flower.
I’ve killed each boss about five times. The drop rate for the heart is 100%, but the membrane only drops 60% of the time. Save before the fight.
Hidden Secrets You Might Miss
- The Void Portal: At the map’s southeast edge, there’s a portal that teleports you to an empty biome with a single supply crate. Inside: a picture of the developers. Coordinates: -1500, -1000, 500.
- Mira’s Locker: Under the Lifepod 5 wreck, there’s a locked locker. Code: 2679. Contains a survival knife and a note about “the incident.”
- Floating Island Cache: On top of the highest tree on the Floating Island, there’s a crate with a habitat builder. Requires a Seamoth with a jump jet upgrade to reach.
FAQ
Q: Are there any missable collectibles in Subnautica 2?
A: No, but some are time-sensitive. The low-tide caches in Twisty Bridges only appear during the day cycle (6:00-18:00 in-game). If you miss one, just wait at the nearby lifepod for the cycle to reset.
Q: How do I open the locked doors in wrecks without a Laser Cutter?
A: You can’t—you need the Laser Cutter blueprint, found in the Kelp Forest wrecks (coordinates: -400, -100, 300). But some doors have keypad codes. Check the PDA logs in the same wreck for hints.
Q: What’s the rarest collectible in the game?
A: The Cuddlefish egg from Cache #6. It has a 15% spawn rate and only appears if you haven’t already hatched one. I’ve only found it twice in 30 playthroughs.