Subnautica 2: How to Get Rubber & Lucifer Rotsac

TL;DR

• Rubber is crafted at the Fabricator using 2x Lucifer Rotsac.
• Lucifer Rotsac is a glowing orange orb found on the ocean floor near your Lifepod — no tool needed to pick it up.
• Look for the Cradle Shootroot plant — a teal, star-shaped coral with an orange glowing bulb in the center. That orange bulb is the Lucifer Rotsac.
• Best farming area: within 150 meters of the Lifepod in any direction on the open seabed.
• You also get Grease from 1x Lucifer Rotsac — needed for the Wakemaker speed tool.
• After collecting the sac, cut the Cradle Shootroot with the Survival Multitool for bonus Fibrous Pulp.

Rubber is one of the first crafting materials you actually need in Subnautica 2. It goes into Basic Fins, the Standard Air Tank, and the Air Bladder — all essential early survival gear. But to make Rubber, you need something called Lucifer Rotsac. With a name like that, it is no surprise players have no idea what it is or where to find it.

This guide explains exactly what Lucifer Rotsac looks like, where to find it fast, how to turn it into Rubber and Grease, and what to craft with each one. If you are just getting started, our Subnautica 2 beginner tips guide is a good read before heading out.

What Is Lucifer Rotsac?

Lucifer Rotsac is a plant resource found on the ocean floor. It is the raw material you need to craft both Rubber and Grease at the Fabricator. Despite the intimidating name, it is one of the most common plants in the early game biome.

Here is what it looks like:

• It grows on a plant called the Cradle Shootroot — a large, star-shaped coral with thin sea-green leaves tipped with orange.
• At the center of the Cradle Shootroot sits a glowing red or orange round bulb. That bulb is the Lucifer Rotsac.
• At night, the orange glow is very obvious. It almost acts like a light source in dark underwater areas, making it easy to spot during nighttime dives.
• During the day, the glow is less dramatic, but the shape and color still stand out against the seafloor once you know what to look for.

You do not need any tool to collect a Lucifer Rotsac. Just swim up to it and press the interact button. Each plant gives you one Lucifer Rotsac per harvest.

Where to Find Lucifer Rotsac in Subnautica 2

The good news is that Lucifer Rotsac is very common near your Lifepod. You do not have to go far, especially in the early game.

Around the Lifepod — Immediate Area

As soon as you release the Lifepod clamps and start exploring, you will find Lucifer Rotsac on the ocean floor almost immediately. The earliest confirmed location is roughly 84 meters from the Lifepod heading toward the 120-degree mark on your compass. Swim around the seafloor near your starting area and look for those star-shaped Cradle Shootroot plants. The glowing orange center gives them away.

Need to release the clamps first? Check our guide on how to release the Lifepod clamps.

Seabed Around the Starting Biome

Lucifer Rotsac is scattered all over the shallow seabed in the starting biome. They appear both on the open seafloor and sometimes attached to abandoned structures, outposts, and ruined buildings. Once you have done one run collecting them, you will realise they are everywhere. As you become more familiar with the Cradle Shootroot shape, you will start spotting them constantly on every swim.

They start appearing more frequently at depths deeper than roughly 50 meters, so diving down slightly from the surface gives better density.

Near the Lifepod Colony Ruins

The colony ruins close to your Lifepod — including the Welcome Center and surrounding structures — often have Lucifer Rotsac growing on or near them. Any time you are running NOA missions in the early game, keep your eyes on the seafloor nearby. You can collect Lucifer Rotsac on the way to and from mission objectives without making separate farming trips.

Mid-Game: Axum Biome

Once you cross the large gap in the ocean (past the Creature Leviathan) and enter the Axum biome, Lucifer Rotsac becomes much harder to find. There are fewer plants here than in the starter biome. The confirmed location in Axum is on top of the main Research Station — roughly 1,290 meters east of the Lifepod at a depth of 127 meters. There are three Lucifer Rotsac plants here that respawn over time.

If you know you are heading into the Axum biome soon, stock up on Lucifer Rotsac beforehand. Craft a supply of Rubber and Grease before you make that crossing.

Bonus: Cut the Cradle Shootroot for Fibrous Pulp

After you pick up the Lucifer Rotsac from the plant, do not leave yet. Pull out your Survival Multitool and cut the remaining Cradle Shootroot stalk. Doing so gives you Fibrous Pulp — one of the most useful early crafting materials in the game.

Fibrous Pulp is used to make Fiber, which goes into Basic Fins, Fiber Mesh, the Rebreather, and First Aid Kits. It can also be cooked into Oily Salad for food. Every Lucifer Rotsac run is also a free Fibrous Pulp run if you bring your Survival Multitool. Our full guide on how to get Fiber and Fibrous Pulp has more detail on this.

How to Craft Rubber in Subnautica 2

Once you have collected enough Lucifer Rotsac, head to any Fabricator. The one inside your Lifepod works perfectly — it has built-in power and is available from the very start of the game.

Steps to craft Rubber:

1. Open the Fabricator.
2. Go to the Resources tab.
3. Select Basic Materials (second section from the left).
4. Find Rubber in the list — it looks like a black roll.
5. Select it. The recipe requires 2x Lucifer Rotsac.
6. Confirm the craft. You now have Rubber.

That is the entire process. Two Lucifer Rotsac in, one Rubber out. No special unlocks or additional tools required. The Rubber recipe is available by default and does not need to be scanned or discovered first.

Important: A base Fabricator needs power to work. The Lifepod Fabricator runs on its own cell, so use that for early crafting. If you build a Fabricator at your own base, connect it to Solar Panels first. See our guide on what to build in your base first for base power tips.

How to Craft Grease in Subnautica 2

The same plant gives you the ingredients for Grease too. Grease is a different material with its own crafting uses — most importantly the Wakemaker, your first major swimming speed upgrade.

Grease recipe: 1x Lucifer Rotsac = 1x Grease.

There is also an alternate Grease recipe using 2x Halfmoon (a fish). That recipe only appears in the Fabricator menu once you have caught or cooked a Halfmoon. If you only see the Lucifer Rotsac version, that is normal — pick up a Halfmoon first to unlock the second option.

Because Grease uses only 1 Lucifer Rotsac versus the 2 needed for Rubber, it is cheaper to produce. Do not neglect it — the Wakemaker it unlocks is a significant quality of life upgrade for exploring the ocean.

What Is Rubber Used For in Subnautica 2?

Rubber is involved in several of the most important early crafting recipes. Here are the key ones:

Basic Fins

Basic Fins require 2x Rubber plus Fiber. This is the first mobility upgrade in the game and makes a noticeable difference to your swimming speed immediately. Without Fins, every dive to collect resources is slower and burns through more oxygen. Craft these as soon as possible. Our guide on how to swim faster in Subnautica 2 covers Fins and other speed upgrades.

Standard Air Tank

The Standard Air Tank requires 1x Rubber, 2x Titanium, and 2x Silver. It increases your maximum oxygen from 45 to 75 — nearly doubling your dive time. This is the single most important early upgrade. It directly enables you to reach Silver caves and go deeper without panicking about oxygen on every swim. See our guide on where to find Silver in Subnautica 2 to gather the other ingredient.

Air Bladder

The Air Bladder requires 1x Rubber and 2x Titanium. It is a consumable emergency device — press the activate key to instantly gain +45 oxygen and shoot toward the surface. It is incredibly useful for escaping dangerous situations and for quickly surfacing when your oxygen is critically low. You can also use it to escape predators. Refills automatically when you surface or enter your base.

For a full survival kit in the early game — Basic Fins, Standard Air Tank, and Air Bladder — you need at least 4 Rubber total, which means collecting at least 8 Lucifer Rotsac. Plan your farming run around that number.

What Is Grease Used For in Subnautica 2?

Grease feeds into machinery and tools that come slightly later in the game. The most important early use is:

Wakemaker

The Wakemaker is a powered swimming tool that significantly boosts your movement speed underwater. It is one of the biggest quality-of-life upgrades in the early game — faster than Basic Fins alone. It requires 1x Grease, 1x Silver, 1x Wiring Kit, and 1x Battery to craft. You need to scan three Wakemaker fragments to unlock the blueprint first. For Titanium farming to support other Wakemaker ingredients, see our Titanium guide.

Lucifer Rotsac Farming Tips

• Always bring your Survival Multitool. Collect the Lucifer Rotsac first, then cut the Cradle Shootroot for free Fibrous Pulp. One pass gives you two resources at once.
• Farm at night. The orange glow is much brighter and easier to spot in dark water. Night diving for Lucifer Rotsac is genuinely faster than daytime because the plants stand out so clearly.
• Bring a Portable Locker. Lucifer Rotsac is common enough that you can fill your inventory quickly. A Portable Locker lets you carry overflow without cutting the run short.
• Collect more than you think you need. Your first full survival kit needs 8 Lucifer Rotsac for Rubber alone, plus extra for Grease. Collect at least 12 on your first dedicated run to have a buffer.
• Rotsac respawn over time. If you clear an area, come back later and the plants will have regrown. The Axum biome Research Station plants reset continuously, making it a reliable mid-game farming spot.
• Watch out for the Cherimoya Rotsac. This looks similar to the Lucifer Rotsac in inventory thumbnails but is a different item. Only the Lucifer Rotsac is used for Rubber and Grease. Check the item name before crafting.
• Craft Rubber first, Grease second. In the early game, prioritise Rubber for survival upgrades. Once you have Basic Fins, an Air Tank, and an Air Bladder, shift focus to Grease for the Wakemaker.

How Many Lucifer Rotsac Do You Need?

Here is a quick reference for how many Lucifer Rotsac you need to craft the most important early items:

• Basic Fins — 2x Rubber = 4x Lucifer Rotsac
• Standard Air Tank — 1x Rubber = 2x Lucifer Rotsac
• Air Bladder — 1x Rubber = 2x Lucifer Rotsac
• Wakemaker — 1x Grease = 1x Lucifer Rotsac

Total for a complete early survival loadout: at least 9 Lucifer Rotsac. Collect 12 to 15 on your first run to have spare Rubber for additional recipes later.

Summary: How to Get Rubber Fast

1. Swim to the open seabed around your Lifepod and look for the Cradle Shootroot — the star-shaped teal coral with an orange glowing orb at the center.
2. Press interact to pick up the Lucifer Rotsac. No tool needed.
3. Cut the Cradle Shootroot with your Survival Multitool for bonus Fibrous Pulp.
4. Collect at least 8 Lucifer Rotsac for a full early crafting session.
5. Return to the Lifepod Fabricator, go to Resources > Basic Materials, and craft Rubber (2x Lucifer Rotsac = 1 Rubber) and Grease (1x Lucifer Rotsac = 1 Grease).
6. Use the Rubber to craft Basic Fins, the Standard Air Tank, and the Air Bladder right away.

Rubber is one of those resources that seems confusing at first only because Lucifer Rotsac has such an unusual name. Once you spot that glowing orange bulb for the first time, you will wonder how you ever missed it. They are genuinely everywhere in the starting biome.

Need more crafting help? Check out our guides on how to unlock blueprints and crafting recipes, how to cure Digestive Incompatibility, best early food sources, and how to play co-op with friends. Grab the game on Steam or Xbox Game Pass if you have not already.