Subnautica has a lot of resources to hunt down, but one of the earliest you'll need to find is cave sulphur, an elusive substance used for building certain electronics. We'll be going over where to find it, how to get it, and how best to use it later on.
Where to Find Cave Sulfur
Cave sulfur exists in the same area as your crashed pod, the colourful coral reef referred to as "The Shallows." However, you can't get to it without dealing with one of the most dangerous things there - the red, balloon-shaped "Crashfish."
Cave Sulfur is found inside squat, brown sulfur plants found randomly inside the Shallows' claustrophobic cave systems, found simply by exploring the ocean floor for long enough. However, each plant also contains a Crashfish inside it who will try to defend its home to the death.
Getting to the Cave Sulfur and Dealing With Crashfish
Once you get close to a sulfur plant, you'll likely hear a high-pitched shriek - that's the Crashfish getting territorial and preparing to charge at you. Immediately check to see where it's coming from, and put as much distance between you and it as possible. These angry little balls explode after a few seconds, and if you're too close to one, it'll knock off a substantial portion of your health. Use the seaglide if you've built one to get away quickly, or move around the caves so the ugly creature gets stuck on a rock. You'll hear the explosion when it finally detonates, leaving the plant safe to harvest.
At this point, you just need to approach the open plant and look at the yellow substance inside. Click on it, and you'll be rewarded with one portion of cave sulfur.
What to Use Cave Sulfur For
Cave sulfur is used only for early-game crafting, with no application beyond being used to build certain kinds of tools. Using it in the fabricator with certain other materials will allow you to build the following:
- Repair tool: Cave sulfur x1, titanium x1, silicone rubber x1
- Laser cutter (requires scanning fragments): Cave sulfur x1, diamond x2, battery x1, titanium x1
- Flares x5: Cave sulfur x1
Now that you're equipped with cave sulfur, why not check out our guide to building titanium ingots, or our how-to on finding/building the Seamoth Submarine? Or you could see our full plot summary and explanation of Subnautica, allowing you to understand everything going on around you.