The Laser Cutter in Subnautica has only one purpose: Cutting holes in Sealed Doors, in the wreckage of the Aurora. We were able to get through the large wreck near Lifepod 17 without it, but the Laser Cutter will be required for our next large wreck exploration.
Finding Laser Cutter Fragments
In order to fabricate the Laser Cutter blueprint you’ll need to scan 3 Laser Cutter fragments. They can be found frequently in crates on the seabed in the Grassy Plateaus biome.
Also if you’ve already explored the large wreck near Lifepod 17 then you almost certainly have found enough Laser Cutter fragments to fabricate the blueprint.
Finding 2 Diamonds for the Laser Cutter
You need 2x Diamond in order to fabricate the Laser Cutter. Diamonds can only be obtained by breaking Shale Outcrops.
Most of the areas where Shale Outcrops can be found are beyond your Seamoth’s current depth limit of 200m, but you can swim deeper without it.
The easiest way to obtain the needed Diamonds, however, is to visit the Mountain Island where the Shale Outcrops can be harvested from the cave walls.
Fabricating the Laser Cutter
In addition to the 2x Diamonds you’ll also need 1x Battery, 1x Titanium, and 1x Cave Sulfur to fabricate the Laser Cutter.
Using the Laser Cutter
Make sure to bring the Laser Cutter on any trip where you may be exploring wreckage. If you come across a burnt-looking door, approach it. You’ll see a message saying Sealed door – Cut to Open.
Use the Laser cutter on the sealed door and eventually you’ll cut out a hole that you can pass through.