Tank Configuration

The tank configuration section sits below the depth and time inputs. Here you define the gas supply for your dive -- from a single recreational tank to a full technical setup with multiple bottom and decompression gases.

Adding a tank

Click Add Tank to add a new tank to your dive plan. Each tank has the following settings:

Setting	Description
Volume	Tank size in liters (e.g., 12 L, 15 L)
Type	Tank type (aluminum, steel)
Count	Single tank or twins (doubles)
O2 %	Oxygen percentage in the mix (21% for air, higher for nitrox)
He %	Helium percentage for trimix blends (0% for air/nitrox)
Role	Designate the tank as Bottom gas or Deco gas

Tank configuration section showing a bottom gas and a deco gas configured -- planner-tanks-light.png / planner-tanks-dark.png

Gas mix fields

When adding or editing a tank, you set the gas mix using two fields:

• O2 % -- Oxygen fraction. Set to 21 for air, 32 for EAN32, 50 for deco 50, 100 for pure O2, etc.
• He % -- Helium fraction. Leave at 0 for air or nitrox. Set higher for trimix (e.g., 35% He for a 18/35 trimix). The balance is automatically calculated as nitrogen.

Adding a new tank showing gas mix fields for O2% and He% -- planner-tank-add-light.png / planner-tank-add-dark.png

Bottom gas vs. deco gas

Each tank must be designated as either a bottom gas or a deco gas:

• Bottom gas is breathed during the descent and bottom phase of the dive. In a single-level plan, this is the gas used at your target depth. In a multi-level plan, you can assign different bottom gases to different levels.
• Deco gas is used during the ascent and decompression stops. The planner automatically switches to deco gas during ascent when the current depth reaches the gas's Maximum Operating Depth (MOD), based on your PPO2 settings.

Loading saved tanks

If you have saved tank presets on your Dashboard, you can load them directly into the planner instead of configuring each tank from scratch. Click the Load Saved Tank button to browse your presets and add them to the current plan.

Gas switching during ascent

When one or more deco gases are configured, the planner handles gas switches automatically during the ascent phase:

1. The planner calculates the MOD for each deco gas based on its O2% and your deco PPO2 limit.
2. During the computed ascent, when the diver reaches a depth at or above the MOD of a deco gas, the planner schedules a gas switch.
3. The gas switch strategy (switch exactly at MOD vs. switch at the next deco stop) is controlled by your Diver Profile settings.
4. Gas switch time is also configurable in the diver profile.

MOD validation

The planner validates the Maximum Operating Depth for every gas in your plan. If your planned depth exceeds the MOD of an assigned bottom gas, you will see a warning. Always verify that your gas mixes are appropriate for your planned depth range.

Tips

• Start with a single bottom gas for simple recreational dives. Add deco gases only when planning decompression dives.
• For trimix dives, ensure your helium percentage is set correctly -- the planner uses it for both narcotic depth (END) and decompression calculations.
• Use the saved tanks feature to avoid re-entering your usual configurations for every new plan.