Walkthrough (Below Zero)

This page serves as a full-game survival mode walkthrough of Subnautica: Below Zero. It also contains gameplay tips and helpful pointers for successfully mastering the oceans. Keep in mind that this page will have spoilers, as it also summarizes the events as you follow along with the story. Note that if at any point in the playthrough you become unable to progress due to a bug, check Console Commands to see if any commands can help.

Background

You play as Robin Ayou, an employee for Xenoworx: An Alterra Initiative, who stealths her way onto the planet 4546B. Robin's mission is to investigate the death of her sister, Sam Ayou.

Beginning

Intro Site

The story starts with Robin crashing in a shuttle pod launched from a passing freighter during a meteor storm. After the intro cutscene, you gain control of Robin. You can use the W A S D keys to walk, Left Shift to sprint, and move your mouse to look around. You will get a Databank Entry. The game instructs you to press Tab to open the PDA in order to check the entry, which is an essential tool in Subnautica: Below Zero. There are some supplies on the ground; collect them. There should be 3 Filtered Water Bottles, 3 Nutrient Blocks, and 9 Flares. If you're having trouble finding everything, consider turning on the "Highlight interactable" setting in the options menu, under Accessibility. While exploring outside the water you should pay attention to your body heat. If hypothermia becomes imminent, you can warm yourself up with the help of Thermal Lilies or the burning wreckage of your shuttle. You can cross a path to an open water area from which you can swim to the Drop Pod.

Open Ocean

Stranded

The path exits into the main area of gameplay, known as Sector Zero. The exact biome you are now in is the Shallow Twisty Bridges.

At this point, your food bar should be at about half. Food & Water are two core gameplay threats that need to be managed constantly. To refill food and water, Robin must eat and drink. The Filtered Water and Nutrient Blocks collected at the crash site will not last forever, and you need to learn to live off the land. Cooked fish can be made using any caught fish at a Fabricator. You can also eat Cured Fish, which are fabricated from fish and Salt Deposits. You will drink Filtered Water, which can be crafted using Bladderfish. There are edible flora in the area such as the Bullseye Shroom which is very prevalent and easier to catch than fish, but require harvesting with a Survival Knife and provide less nutrition.

Also present is the health bar, which monitors how much damage you can take before dying. Damage usually comes from predatory fauna or flora, though it can also be caused by fall damage and excessive temperatures. Healing requires the use of First Aid Kits, but health will also slowly regenerate if you've refilled your food and water meters enough.

Finally, the last two indicators are Oxygen and Temperature. When underwater and in bases/vehicles without power, oxygen slowly runs out at a pace of 1 unit per second, and faster if your depth is below 100 meters and you don't have a Rebreather equipped. Temperature, on the other hand, decreases when outside of water and in cold environments. Note that the speed at which temperature decreases depends on the biome and the current weather.

Shortly after exiting the path, Robin arrives at the Drop Pod, a safe location for Robin to store and craft items. Inside the Drop Pod is a 6×8 storage locker and a Fabricator, one of the most essential crafting machines in the game. The Fabricator has four tabs: Resources, for crafting items that are used to craft final products; Sustenance, for crafting food and water; Personal, for crafting Equipment and Tools; and Deployables, useful items that are placed into the world and have a handy effect. Right now, there are three items of vital importance to craft: the Survival Knife, the Scanner, and the Standard O₂ Tank.

Important Tools

The quickest tool to craft is the Scanner. Its recipe is one Battery and one Titanium. Titanium can be acquired by breaking open Limestone Outcrops, which litter the floor and walls of many Biomes, including the one you are currently in. The outcrops also drop Copper Ore, which is required to craft batteries. The other resources needed for batteries are two Ribbon Plants, which are small, narrow, yellow and green plants generally found in the caves of the Shallow Twisty Bridges. Once you have all the items you need, return to the Drop Pod to craft the Scanner. The Scanner allows you to scan fauna, flora, rocks, and most importantly, Fragments. Fragments are broken pieces of technology that litter the floors of many biomes. Each biome has a different array of fragments. One very useful piece of technology that can be scanned in the Shallow Twisty Bridges is the Seaglide, which greatly increases your movement speed. Note that it and the Scanner require a charged battery to operate. If your tool runs out of power, simply craft another battery and replace it by pressing R while holding the tool. Later on in the game you'll be able to create a Battery Charger and place it in your base to recharge the batteries you have.

The next important item is the Survival Knife. The knife allows you to collect certain resources and fight off aggressive life forms should the need arise. The knife's recipe is one Titanium and one Silicone Rubber. Silicone Rubber can be crafted by harvesting a Seed Cluster in the Arctic Kelp Forest. One of the forests can be found in the direction away from the tunnel. Once you make your way there, the seed clusters are bright red bulbs hanging off the tall Creepvines, which resemble real-life kelp. It is prudent to harvest as many as you can carry, as you will need more later. Once you have everything you need, head back to the Drop Pod to fabricate the knife. After crafting the knife, you will be able to harvest and eat edible flora such as the Bullseye Shroom or even Creepvine Samples if necessary.

The third item that is necessary to craft is the Standard O₂ Tank. The tank increases your total oxygen, allowing you to stay underwater much longer. Its crafting recipe is two Titanium and a Fiber Mesh. Fiber Mesh is crafted using two Creepvine Samples, which can be acquired by using the Survival Knife on a Creepvine in the Arctic Kelp Forest. To use the knife, simply equip it using the number keys and then click RMB. Once you craft the tank back at the Drop Pod, several more crafting recipes will be unlocked.

While not strictly necessary, there are some other tools you can craft. One is the Flashlight, and the other is the Air Bladder. The Flashlight simply requires a Battery and Glass. The Flashlight can help you search for materials in the dark, as the world can be very poorly lit in certain places, especially around night. Glass is crafted by combining two Quartz. You may have already seen quartz; it is a white, crystalline object found on the floors of the Shallow Twisty Bridges. The Air Bladder requires Silicone Rubber and a Bladderfish, and can be used in two different ways. The first way is by replenishing your oxygen meter with 15 seconds of air. The other, more useful way is by allowing Robin to rapidly ascend ~170 meters from the ocean floor to the water surface. The speed at which the player ascends is faster than most predators, making this a useful escape tool while in a pinch.

Supplies

After heading west of the Drop Pod, towards the Sparse Arctic and the Arctic Kelp Forests, the PDA locates an emergency supply cache in the Arctic Kelp Forest and adds the beacon to Robin's PDA. The supply cache contains the blueprint for the Compass, which puts a compass on the player's HUD. Additionally, the player can find a PDA with a conversation between Fred Lachance and Sam Ayou. The beacon for the cache can be turned off in the beacons tab of the PDA or taken to be placed in another point of interest. Something you should take the time to craft is the High Capacity O₂ Tank, an upgraded version of the Standard O₂ Tank you previously crafted. Though not absolutely necessary to progress, if you are an inexperienced player it is recommended to craft this upgrade. The blueprint for it can be found in the tech site in the Twisty Bridges; just explore until you find it, or skip to the next section if you can go without. A good landmark to look for is a big dropoff by the small area behind and to the left of your pod with Creepvine in it; you'll know you've found it when you see a cluster of Ribbon Plants at the bottom. Its recipe calls for four Titanium, two Glass, and one Silver Ore. In total, you need four quartz for the tank. Silver ore is trickier to find; it is available in the Arctic Kelp Caves (where you went earlier for the supply drop) and the Twisty Bridges. The former is safer, as it has no predators, but can be easy to get lost in. It is also significantly easier to find the Twisty Bridges, as they are just trenches surrounded by some parts of the Shallow Twisty Bridges, whereas Arctic Kelp Caves entrances are few. Whichever you decide, you must look for Argentite Outcrops, which are grey rocks protruding from the surface of walls. Once you have everything you need, head back to the Drop Pod to craft the tank. Remember to take off your old tank in order to craft the new one.

Sanctuary Zero

Finding the Sanctuary

If you explore the Twisty Bridges, you will receive an SOS signal originating from the sanctuary. The sanctuary is located deep in the biome, at a depth of 180m. You can find the entrance by going farther away from the Drop Pod, opposite the direction the area of Robin's crashed shuttle. Once you get near the sanctuary, you may see some alien pillars; if you're approaching them from the direction of your drop pod, they'll be to the right of the trench. Follow the pillars to find the sanctuary, which is another large alien structure with a wide, square facade. Going through the opening will take you out of the water and back onto your feet.

The Download

The first thing in front of you is the cave of the sanctuary. The entrance to the inner sanctuary contains three Ion Cubes, which you may want to pick up as they are not very common. Be sure not to waste them as they will be required to progress, though more can be found around Sector Zero. Follow the rocky path to get to the inner sanctuary, which is marked by more alien structures. Inside the inner sanctuary is a large, open room with a giant cube-like structure in the center. Along the way, you'll get a message telling you the facility's power is low. An alien, disembodied voice speaks to Robin and says it is running out of time. The facility tells Robin that "a storage capacity is found on her person". Go around the cube and up the ramp to find a green hologram. Interacting with the hologram initiates a cutscene in which an Architect consciousness is downloaded into Robin's brain. Once Robin regains consciousness, she and the alien talk to each other and Robin becomes upset about what happened. The alien becomes silent while it thinks of a solution for their current situation. Finally, the Sanctuary Cube collapses. You can now exit the sanctuary.

Leaving the sanctuary

After Robin exits the Sanctuary, the Architect's voice tells her it needs a body to transfer itself into. The voice tells her it belongs to a species called the Architects. Robin asks for its name, so it tells her she may append her seed code to his species designation. The voice concedes that Robin may call it Al-An.

Delta Island

The Delta Island

In the next days after the landing the game will give you the exact location of the Delta Island. It is in the center of Sector Zero that holds the Communications Tower, a large installation to monitor activity in Sector Zero. Head towards the island, which can be seen from a fair distance to the South (away from the tunnel and mountains).

When you get to the island, you must then climb it towards the top where the tower resides. Go through the caves to reach it. It is at this point that the player will most likely face the dangers of hypothermia for the first time. On the Delta Island, Thermal Lilies or hot springs with Crystalline Sulfur provide a very convenient source of heat that makes surviving the island very easy. On her way to the top, Robin will trigger a cutscene involving Marguerit Maida, who tells her to stay off "her" land and then leaves in her modified Prawn Suit. Your PDA will mark a signal showing her last tracked position. Remember it for later.

Delta Station

Once at the top of the island, you will most likely see Delta Station before seeing the tower. By the base is a fragment of Habitat Builder. The habitat builder allows Robin to build Seabases in the water or on land. Seabases allow you to have a base away from the Drop Pod, which can contain storage and useful facilities such as a Fabricator. See Seabases and Hull Integrity for more information.

There are also certain scannable objects in the base. Most do not have a use other than vanity, however two specific objects stick out as extremely useful; the Multipurpose Room and the Modification Station. The room can be scanned from the outside (it is the large round room, there are two of them), and the Modification Station is found inside the bedroom of the base. It can be used to build upgrades to certain equipment and tools, such as the knife and the oxygen tank. After scanning everything you need or want, exit the base and head up the stairs in front of you to the radio tower. It is also revealed that the Delta Station quartered the following members: Fred Lachance, Jeremiah Murgle, and Emmanuel Desjardins.

Communications Tower

At the very peak of the island, Robin can walk up the Communications Tower. There are a couple of PDAs nearby, most of which were abandoned by Jeremiah Murgle. A terminal c