Getting started
Your first dive plan
A short, hands-on walkthrough: pick a nitrox mix for a planned depth, then check how much gas the dive will use.
Last updated 3 Haziran 2026
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What you will do
This walkthrough takes you through two everyday planning tasks end to end. You will plan a recreational dive to 30 metres on nitrox. First you pick a good mix for that depth. Then you check whether one cylinder holds enough gas for the dive. Both tools live in the Plan tab.
The numbers below are an example. Swap in your own depth, cylinder, and breathing rate as you go.
Step 1: Pick a mix for your depth
The Best Mix tool finds the richest nitrox or trimix you can safely breathe at a given depth, so you stay well clear of oxygen toxicity.
Open Best Mix
From the Plan tab, tap Best Mix.
Set your planned depth
Drag the MOD slider (maximum operating depth) to your deepest planned point. For this example, use 30 m (100 ft). As you move it, the O₂ slider reads back the matching oxygen percentage automatically.
Pick your PPO₂ limit
The oxygen partial pressure (PPO₂) limit decides how rich a mix you can breathe. Use the Max PPO₂ toggle to pick a limit: 1.2, 1.4, 1.6, or Custom. A common working limit is 1.4. PPO₂ is always in bar, whatever your other units are set to.
Read the recommended mix
The tool shows the best nitrox for that depth. At 30 m (100 ft) and a 1.4 bar limit, that lands on EAN35 (35% oxygen). It also shows the gas specs at that depth, including the maximum operating depth (MOD), so you can confirm 30 m is within the mix’s range.
You now have a target mix. Mix it yourself with the Gas Blender, or note it for your fill station. The Best Mix calculator page explains every field.
Step 2: Check how much gas you need
The Gas Usage tool estimates how much gas a dive consumes, so you can confirm your cylinder is large enough and work out a turn pressure.
Open Gas Usage
Go back to the Plan tab and tap Gas Usage.
Set your cylinder
Enter your cylinder size and starting pressure. For example, a 12 L (about 80 cu ft) cylinder filled to 200 bar (about 3000 psi).
Enter your breathing rate
Enter your surface breathing rate. The field is labelled SRMV (surface respiratory minute volume). A typical recreational value is around 20 L/min (about 0.7 cu ft/min). If you do not know yours, calculate it from a real dive with the SAC / SRMV calculator.
Add the dive
Enter the planned depth and bottom time, for example 30 m (100 ft) for 20 minutes, then tap Add to Plan to push the step into your Dive Profile.
Read the result
Once you add a step, the Summary shows the gas the dive consumes, in both pressure and volume, and what you have left against your reserve. The reserve it checks against follows your gas reserve rule (rule of thirds by default), set in settings, with a hard floor of 50 bar. If the cylinder runs short, you can plan a bigger cylinder, a shorter dive, or a shallower profile before you get wet.
The Gas Usage page covers cylinders, multiple dive segments, and reserve rules in full.
You have a plan
With those two steps you have a mix that suits your depth and confidence that your cylinder carries enough gas. That is a complete recreational plan in well under five minutes.
When you are ready for staged decompression, multiple gases, or rebreather dives, move on to the Deco Planner (shown as “Deco Plan” on the Plan tab). It builds a full stop schedule and handles gas switching for you.
Related
- Best Mix calculator finds the right mix for a depth.
- Gas Usage estimates consumption and turn pressure.
- SAC / SRMV calculator works out your personal breathing rate.
- Deco Planner plans staged decompression dives.
Parts of this guide were drafted with AI assistance and may contain mistakes. It's educational, not a substitute for training. Always dive within your certification and verify with your instruments.