SDI MOD teaching

[boulderjohn]

Seven years ago someone posted a question about MOD's in the SSI forum. It asked about something that he encountered in what he thought was SSI instruction. Someone else recently posted in that thread, pointing out that the course material quoted was actually from SDI, not SSI, and he said that he saw it when taking the SDI course himself. Here is what the course materials apparently say:

"Many Nitrox divers make life even easier. They pick EAN40 for all dives shallower than 30 m/99 ft as this gives the most bottom time and pick EAN32 for dives right up to the maximum sport diving depth limit of 40 m/132 ft."

Doing what the course advocates means accepting 1.6 as the maximum PPO2 rather than the more common 1.4. Since the person was originally asking of that was indeed SSI policy (and was told it was not), I am transferring this question to the SDI forum.

Here is the original thread:

Thread 'Nitrox Rule of Thumb 32 vs 40'

Jul 29, 2018

From SSI

"Many Nitrox divers make life even easier. They pick EAN40 for all dives shallower than 30 m/99 ft as this gives the most bottom time and pick EAN32 for dives right up to the maximum sport diving depth limit of 40 m/132 ft."

My question : Why the higher EAN for shallower dives vs low EAN for deeper dives?


Seeking to understand

Thank you

• apivonka
• ean 32 shallow and ean 40 deep
• Replies: 40
• Forum: SSI: Scuba Schools International

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