Understanding First Oxygen And Water Guide
Maintain oxygen and water during the first days
This is an original reference for the first Subnautica. Your current depth rating, oxygen, available tools and navigation route determine when an objective is practical. Follow actual in-game PDA and Fabricator information for any values that vary by version.
How to use this information
Learn which foods spoil, which drinks you can fabricate and how air limits constrain every dive.
What to avoid
Do not wait for oxygen warnings at the deepest point of a cave.
Step-by-step guide
Understand oxygen and ascent time
Understand oxygen and ascent time is a concrete milestone in this survival route, not a command to rush to the next depth. Start with Oxygen Budget. Oxygen is a time limit on every dive outside breathable air or a vehicle with functioning life support. Reserve enough air to return along the actual route, allowing time for navigation errors. The most common failure here is specific: Using the full tank at the destination leaves no buffer for the way back. Before leaving your staging point, review the equipment in your PDA, verify the depth of the objective and note which corridor you will take back. If you have not unlocked the required technology, scan fragments in known terrain and do a separate supply trip rather than risking all resources at once. The next connection is Bladderfish: A small purple fish that can be converted into filtered water early on. Collect several when establishing an early hydration routine near Lifepod 5. Those two topics form a useful checkpoint: finish the present task, repair any worn equipment, refill oxygen or cells, and update Beacons before you continue. Remember the related limitation: Do not rely on random fish catches alone once deeper expeditions become routine. On this original-Subnautica route, a sensible plan is more valuable than a fixed set of unverified coordinates. Use this chapter as a decision path for your own save rather than assuming all fragments and resources have been found already.
Collect Bladderfish for filtered water
Collect Bladderfish for filtered water is a concrete milestone in this survival route, not a command to rush to the next depth. Start with Bladderfish. A small purple fish that can be converted into filtered water early on. Collect several when establishing an early hydration routine near Lifepod 5. The most common failure here is specific: Do not rely on random fish catches alone once deeper expeditions become routine. Before leaving your staging point, review the equipment in your PDA, verify the depth of the objective and note which corridor you will take back. If you have not unlocked the required technology, scan fragments in known terrain and do a separate supply trip rather than risking all resources at once. The next connection is Peeper: A small edible fish common in early-game waters, useful for starting food supplies. Use a Fabricator for cooked food when you intend to eat it soon; cured food behaves differently. Those two topics form a useful checkpoint: finish the present task, repair any worn equipment, refill oxygen or cells, and update Beacons before you continue. Remember the related limitation: Cooked food stored for long trips can spoil; do not overpack it. On this original-Subnautica route, a sensible plan is more valuable than a fixed set of unverified coordinates. Use this chapter as a decision path for your own save rather than assuming all fragments and resources have been found already.
Prepare cooked food for short trips
Prepare cooked food for short trips is a concrete milestone in this survival route, not a command to rush to the next depth. Start with Peeper. A small edible fish common in early-game waters, useful for starting food supplies. Use a Fabricator for cooked food when you intend to eat it soon; cured food behaves differently. The most common failure here is specific: Cooked food stored for long trips can spoil; do not overpack it. Before leaving your staging point, review the equipment in your PDA, verify the depth of the objective and note which corridor you will take back. If you have not unlocked the required technology, scan fragments in known terrain and do a separate supply trip rather than risking all resources at once. The next connection is Rebreather: An equipment piece that helps reduce oxygen penalties at greater depths. Craft before deeper free-diving; pair with larger tanks and a clear ascent route. Those two topics form a useful checkpoint: finish the present task, repair any worn equipment, refill oxygen or cells, and update Beacons before you continue. Remember the related limitation: It does not increase a vehicle's depth rating. On this original-Subnautica route, a sensible plan is more valuable than a fixed set of unverified coordinates. Use this chapter as a decision path for your own save rather than assuming all fragments and resources have been found already.
Improve your oxygen tank and Rebreather
Improve your oxygen tank and Rebreather is a concrete milestone in this survival route, not a command to rush to the next depth. Start with Rebreather. An equipment piece that helps reduce oxygen penalties at greater depths. Craft before deeper free-diving; pair with larger tanks and a clear ascent route. The most common failure here is specific: It does not increase a vehicle's depth rating. Before leaving your staging point, review the equipment in your PDA, verify the depth of the objective and note which corridor you will take back. If you have not unlocked the required technology, scan fragments in known terrain and do a separate supply trip rather than risking all resources at once. The next connection is Water Filtration Machine: A powered habitat machine that produces drinking water and salt. Place in a powered seabase to stabilize long-term hydration. Those two topics form a useful checkpoint: finish the present task, repair any worn equipment, refill oxygen or cells, and update Beacons before you continue. Remember the related limitation: It consumes significant power and does not work without a functioning base grid. On this original-Subnautica route, a sensible plan is more valuable than a fixed set of unverified coordinates. Use this chapter as a decision path for your own save rather than assuming all fragments and resources have been found already.
Develop sustainable base water production
Develop sustainable base water production is a concrete milestone in this survival route, not a command to rush to the next depth. Start with Water Filtration Machine. A powered habitat machine that produces drinking water and salt. Place in a powered seabase to stabilize long-term hydration. The most common failure here is specific: It consumes significant power and does not work without a functioning base grid. Before leaving your staging point, review the equipment in your PDA, verify the depth of the objective and note which corridor you will take back. If you have not unlocked the required technology, scan fragments in known terrain and do a separate supply trip rather than risking all resources at once. The next connection is Oxygen Budget: Oxygen is a time limit on every dive outside breathable air or a vehicle with functioning life support. Reserve enough air to return along the actual route, allowing time for navigation errors. Those two topics form a useful checkpoint: finish the present task, repair any worn equipment, refill oxygen or cells, and update Beacons before you continue. Remember the related limitation: Using the full tank at the destination leaves no buffer for the way back. On this original-Subnautica route, a sensible plan is more valuable than a fixed set of unverified coordinates. Use this chapter as a decision path for your own save rather than assuming all fragments and resources have been found already.