Crash Powder is a sulfur-based raw material found in Subnautica’s shallow caves. It is a key component for crafting the Welder, which you will need to build and repair things. This guide will walk you through the process of finding, and obtaining Crash Powder so that you can then progress further into your survival story in Subnautica.
The first thing you need to do is head out of your escape pod, and into the water. Once in the water you will need to locate any type of outcropping of rock that looks like it leads into a cave-like area. Enter the cave, careful not to venture too deeply into darker caves without a Flashlight, and listen for the sound of a creature hissing.
This creature is the Crash fish, which resides in Crash Plants, which hold the valuable resource you are trying to obtain. Once you hear the hiss, that means the Crash fish has left the plant, and is currently making its way towards you. Be careful not to let them get to close, or the explosion will hurt you, and possibly kill you if you are weak enough.
Some options to help you deal with Crash fish include but are not limited to: pushing it into a wall using the Repulsion Cannon, and shooting it with the Stasis Rifle to immobilize it. The creature will still explode in both instances, however, this is a helpful way to deal with the Crash fish if you aren’t willing to risk them catching up to you.
Alterantively, you can also outrun the Crash fish using the SeaGlide or PowerGlide, just make sure your battery isn’t close to running out.
Once you have lured the Crash fish away from the Crash Plant, and effectively destroyed the fish, loot the Crash Powder from the plant, but make sure you don’t destroy the plant, otherwise the Crash fish will not respawn, and you will no longer be able to loot the plant for Crash Powder.
Now that you have Crash Powder, it’s time to make your first Welder, which is easily one of the most powerful and important tools in the entire game.
Head back up to your escape pod and make your way back inside by boarding your escape pod. Once inside make sure you have Magnesium, Crash Powder, and Titanium inside your player inventory as you will need all three components to be able to craft the Welder. Next you need to open up the Fabricator and select the Welder from the list of craftable objects. To find the Welder navigate to Personal > Tools in the Fabricator creation list.
Once you have crafted the Welder, you can then repair the various parts of your escape pod, as well as craft actual base pieces underneath the surface of the water. Crash Powder is also used to craft Flares in the Fabricator, which can be very useful for lighting up dark caves, and exploring the ocean after sunset.