How to Fill a Standard O₂ Tank

Crafting the Tank

A Standard O₂ Tank is the first air supply you can build. Craft it from Titanium Ingot and Fiber Mesh at a crafting table. Fiber Mesh is itself crafted from materials you gather while diving, so collect those first.

Filling the Tank

Once you hold a Standard O₂ Tank, you need to charge it before it is useful underwater. The tank is filled using a Power Cell. Place a Power Cell and your Standard O₂ Tank together in a crafting grid to transfer the charge into the tank. Keep spare Power Cells on hand so you can refill between dives.

When the tank runs low during a dive, surface and repeat the Power Cell transfer. If you want longer bottom time, upgrade to a High Capacity O₂ Tank, which holds more air, or a Reinforced O₂ Tank for tougher conditions. Each upgrade still uses the same Power Cell refill method.

Practical Tips

• Carry two Power Cells: one to fill with, one as backup.
• Refill before every long descent rather than mid-dive.
• Pair the tank with a Diving Mask so you can see clearly while breathing.
• If you plan to go deep, craft Reinforced Wetsuit Leggings to survive the cold.