Equivalent Air Depth (EAD) explained
Equivalent Air Depth (EAD) helps divers compare nitrogen exposure when using nitrox. This guide explains what EAD means and how it fits into basic dive planning.
- EAD compares nitrogen exposure when diving nitrox.
- It shows what depth on air would feel equivalent.
- Lower EAD means less nitrogen loading.
What is EAD?
Equivalent Air Depth (EAD) is the depth at which a diver breathing air would experience the same nitrogen exposure as a diver breathing nitrox at a given depth.
Why EAD matters
Nitrox reduces nitrogen content compared to air. EAD helps divers understand how much that reduction affects nitrogen loading during a dive.
- It helps explain longer no-decompression limits
- It simplifies comparison between air and nitrox dives
- It is commonly used in basic nitrox training
EAD and nitrox
When diving nitrox, the actual depth may be the same, but nitrogen exposure is lower. EAD expresses that reduced exposure as a shallower depth on air.
- Actual depth: deeper
- EAD: shallower
- Result: less nitrogen loading
Simple example
A diver using nitrox at a certain depth may have an EAD that is several meters shallower than the actual depth, meaning their body absorbs nitrogen as if the dive were shallower.
Limitations of EAD
EAD only considers nitrogen exposure. It does not account for oxygen exposure, which is why EAD must always be used together with MOD and ppO₂ planning.
- EAD does not replace MOD calculations
- Oxygen limits still apply
- Dive computers handle this automatically, but understanding helps
Quick checklist
- ✅ Confirm oxygen percentage
- ✅ Know your EAD for the planned depth
- ✅ Check no-decompression limits
- ✅ Respect MOD and ppO₂ limits
- ✅ Set dive computer correctly
FAQ
Is EAD still relevant with dive computers?
Yes. While computers calculate everything automatically, EAD helps divers understand why nitrox allows longer no-decompression limits.
Does EAD affect oxygen exposure?
No. EAD only relates to nitrogen. Oxygen exposure must be managed separately using ppO₂ and MOD.
Is EAD used in recreational diving?
Yes. It is commonly taught in recreational nitrox courses as a planning concept.
Dive computers make EAD calculations automatic, but understanding the concept improves planning confidence.
Deals of the week
Featured
