Beacons are hugely important in Subnautica: Below Zero, giving players their first means of tracking where they have been and any important discoveries that they make. A blueprint is required to make it, and this blueprint can be either be found, or derived from scanning a Beacon Fragment.
To go the Beacon Fragment route, players will first need to make a Scanner. Once this is done, they can leave the pod and, if we consider that the pod door is facing north, head northeast in a straight line. They will pass through some kelp, and after about 350 meters will come to some frozen roots. In the distance, they will be able to see a faint blue light.
There are two different platforms in this region with lights on them, and each will have some crates that players can explore. Between them will be the Beacon Fragment. Players can simply scan it to copy the blueprint for themselves, then make their own Beacons using Copper and Titanium in the Fabricator back at the pod.
Once they have beacons, players can use them to mark areas that they they have already explored, give them their own names, and control which beacons are active in the PDA to avoid and overly cluttered screen.