How To Replenish And Increase Maximum Oxygen In Subnautica 2

Do you want to increase your maximum oxygen in Subnautica 2? If you’re playing on Creative Mode, then you don’t need to worry too much since your character can’t die. However, in Survival Mode, your oxygen gets depleted too fast, which makes frequent dives very challenging. Here’s our guide to help you with this particular mechanic.

Subnautica 2 survival guide: Oxygen

In Survival Mode, your character has 45 oxygen by default. This gets depleted at the rate of -1 oxygen per second while you’re underwater. That means you have to find ways to quickly replenish oxygen, as well as methods that increase the maximum amount.

The surface and other safe zones

Swimming to the surface rapidly restores your oxygen in Subnautica 2. This might sound simple, but it can be quite tough when you’re hundreds of meters below sea level. Thankfully, there are safe areas that also help replenish oxygen levels:

• Any base (i.e. corridor/room with a hatch), as long as there’s enough power, restores your oxygen while you’re inside.
• Abandoned habs known as Colonist Bunkers can be entered. These happen to contain biobed upgrades, too.
• Once you’ve built the Tadpole, being inside the vehicle also replenishes oxygen.

Oxygen Tunics and air bubbles

If you’re trekking underwater, then chances are you’ll come across odd-looking blue stems known as Oxygen Tunic. As the name implies, these plants create oxygen, which they spew forth as a bright blue bubble. Swim toward these to replenish your oxygen.

In some cases, you might see air tanks left behind by other divers. These, too, have air bubbles that increase your chances of survival.

Air Bladder usage

One device that you can craft via the Fabricator is called an Air Bladder, which costs 2x Titanium and 1x Rubber. Add it to a slot in your keybinds, then use it to gain +45 oxygen. To refill it, you have to surface or find a safe area like a base or vehicle.

Portable Oxygen Generator usage

The Portable Oxygen Generator is a more advanced contraption. The blueprint itself comes from the Great Jaw, which happens to be a pretty decent Lithium farming spot. Try to avoid its pinkish tendons while scanning the objects. If you’re not careful, the Great Jaw will snap shut, causing acids to dissolve and kill your character.

Once you’ve unlocked the Portable Oxygen Generator blueprint, you can construct it via the Habitat Builder tool. It costs 3x Titanium and 2x Lithium.

• The Portable Oxygen Generator requires 1x Basic Battery to function and you can carry it around with you.
• The device’s oxygen level is refilled over time through electrolysis. If it has a lot when you use it, you’ll gain up to +15 oxygen. If it doesn’t have a lot and it has just refilled a small amount, you’ll gain +5 oxygen.

Standard Air Tank and High Capacity Air Tank

Of course, you can increase your maximum oxygen in Subnautica 2. This is done by crafting Air Tank upgrades via the Fabricator:

• The Standard Air Tank blueprint is available by default. To craft it, you need 2x Titanium, 2x Silver, and 1x Rubber. It increases your maximum oxygen to +75.
• The High Capacity Air Tank, meanwhile, is a more advanced upgrade.
  • It comes from the Research Center/Alien Ruins thousands of meters away from the Lifepod. We recommend checking our mini-walkthrough to help familiarize yourself with the locations. Once you’re done with the objectives in the Tadpole Pens, you’ll learn about the blackbox signal for the Research Center/Alien Ruins.
  • Grab the datapad on a crate that’s in front of the entrance to unlock the blueprint. The upgrade itself requires 1x Standard Air Tank and 1x Plasteel Ingot. The latter is manufactured via the Processor at the cost of 2x Titanium and 1x Lithium.
  • The High Capacity Air Tank boosts your maximum oxygen to +120.

That does it for our guide on how to restore and increase maximum oxygen in Subnautica 2. Don’t forget that there are other methods that help you manage your oxygen levels, such as the Oxygen Control biomod and the use of the Rebreather. If you need more survival tips, you can take a look at our food and water guide.