Lucifer Rotsac is one of the first crafting materials you need in Subnautica 2, because it feeds directly into Rubber and Grease at the Fabricator. Without it, you cannot make Fins, a Standard Air Tank, or an Air Bladder, so progression past the Lifepod stalls quickly.
What Lucifer Rotsac looks like
Lucifer Rotsac is described in the databank as an oily, glowing bulb that has a heartbeat. You do not harvest it from the ground directly. It grows inside a host plant called Cradle Shootroot, which is the bright blue or teal, antler-shaped flora dotted across the shallow seabed.
The bulb itself glows orange (some plants present it as a deeper red-orange), which makes it easy to spot in low light or at night. The Cradle Shootroot has thin sea-green leaves tipped with orange, and the Rotsac sits in the middle like a starfish-shaped core.
Be careful not to confuse it with Cherimoya Rotsac, a similar-looking bulb from a different plant. They are not interchangeable in recipes.
Where to find Lucifer Rotsac near the Lifepod
You can start collecting Lucifer Rotsac the moment you release your Lifepod and dive. No tool is required. The shallow biome around the starting area has several reliable clusters within a short swim.
| Spot | Direction from Lifepod | Distance | Depth |
|---|---|---|---|
| First cluster (three plants) | Toward 120 on the compass | ~84 m | ~12 m |
| Larger line of plants | North, extending east | ~105 m | Shallow seabed |
| Anemone Hills clearing | 330° NW | ~100 m | Sand floor |
| East shallows patch | East | ~70 m | ~15 m |
| Axum biome (Research Station roof) | East, past the Creature Leviathan gap | ~1,290 m | ~127 m |
The northwest route into the Anemone Hills is the most generous for stockpiling. From the Lifepod, head 330° NW and follow the sand floor. The path widens into a clearing around 100 meters out, where Cradle Shootroot plants line the rocks and surround two boulders, giving you more than a dozen bulbs in one sweep.
Across the gap that contains the Creature Leviathan, the Axum alien biome has very few Cradle Shootroot plants. The only consistent spot is the roof of the main Research Station you visit during the main story, where three Rotsac plants regrow continuously.
How to harvest it
Picking up a Lucifer Rotsac is bare-handed.
Step 1: Swim up to a Cradle Shootroot plant until the prompt for the bulb appears in the center of the screen.
Step 2: Press your interact key. The bulb goes straight into your inventory as one Lucifer Rotsac per plant.
Step 3: If you also want crafting fiber, cut the Cradle Shootroot itself with the Survival Multitool. It drops Fibrous Pulp, which feeds into Fiber or an Oily Salad once you have unlocked the Digestion Adaptation from the Angel Root.
Cradle Shootroot plants respawn over time, so marking a productive cluster with a beacon and returning to it is a stable farming strategy throughout the early game.
Turning Lucifer Rotsac into Rubber and Grease
Both recipes use the Fabricator. The one in your Lifepod works out of the box. If you want one at a base, the Fabricator itself costs 1 Titanium, 1 Copper, and 1 Quartz, all of which spawn in the same shallow biome.
Open the Fabricator and move to the Resources tab, second column on the left, under Basic Materials. Rubber and Grease both light up as long as you have Lucifer Rotsac on you or in a connected storage container at your base.
| Output | Station | Cost | Common use |
|---|---|---|---|
| Rubber | Fabricator | 2 Lucifer Rotsac | Basic Fins, Standard Air Tank, Air Bladder |
| Grease | Fabricator | 1 Lucifer Rotsac | Later-game machinery components |
The Fabricator needs power to run. The Lifepod handles that automatically, but a base Fabricator will not produce anything until the structure has a working power source.
Why the recipe might not appear
If Rubber or Grease are greyed out or missing from the Fabricator menu, the cause is almost always one of these:
- The Lucifer Rotsac is stored in a locker that is not part of your base inventory chain. Move it into your personal inventory.
- You picked up Cherimoya Rotsac instead of Lucifer Rotsac. Check the icon and name in your inventory.
- The Fabricator has no power, which can happen at a new outpost before solar panels or another power source are placed.
Subnautica 2 is in Early Access, so spawn density, exact distances, and recipe positions inside the Fabricator menu can shift between patches. The plant identity, the harvest method, and the 2:1 Rubber and 1:1 Grease ratios have been stable so far.