Question 1

What is Equivalent Air Depth (EAD)?

Accepted Answer

Equivalent Air Depth (EAD) is the depth at which breathing air would produce the same partial pressure of nitrogen as the Nitrox mix you're using at your actual depth. It's a way to calculate your no-decompression limits as if you were diving on air, making it easier to use standard air dive tables.

Question 2

How is EAD calculated?

Accepted Answer

The formula is: EAD = (Depth + 10) × (1 - O₂%) / 0.79 - 10. For example, at 30 meters using EAN32 (32% oxygen): EAD = 40 × 0.68 / 0.79 - 10 = 34.4 - 10 = 24.4 meters. This means diving on EAN32 at 30m is equivalent to diving on air at 24.4m.

Question 3

Why is EAD important for Nitrox diving?

Accepted Answer

EAD allows you to use standard air decompression tables while diving with Nitrox. By knowing your EAD, you can accurately calculate no-decompression limits, plan your dive, and reduce your risk of decompression sickness from nitrogen absorption.

Question 4

Does higher oxygen mean lower EAD?

Accepted Answer

Yes, higher oxygen percentages in your Nitrox mix result in a lower EAD at any given depth. This is because there's less nitrogen in the breathing gas. For example, EAN40 has a much lower EAD than EAN32 at the same depth, providing more decompression safety margin.

Question 5

Can I use EAD for deep dives?

Accepted Answer

EAD is primarily useful for recreational diving depths (typically 18-40 meters). For deeper dives or when using complex decompression planning, specialized Nitrox or trimix tables should be used instead of relying on EAD calculations.

Equivalent Air Depth Calculator

Frequently Asked Questions