Split from Exploration dives without a computer

[TheRedHead]

Gue uses a max PPO2 of 1.6 for deco gases.

Why the 1.2 on bottom mix? If I recall correctly, no one has ever toxed on either 1.4 or 1.6 (and I think the source is NOAA). 1.6 severely limits your time, of course.

 

[PerroneFord]

In our class, I think the NOAA, IANTD, and TDI, all gave either 1.3 or 1.4 as max for working portion of the dive and 1.6 as max for deco stops.

 

[TheRedHead]

We do them on a test bench with a calibration test pump and a master gauge.

Isn't that something most shops do with your regular regulator service? Mine does.

 

[PerroneFord]

1.6 severely limits your time, of course.

Could you explain this a bit more? I don't understand.

 

[JeffG]

Why the 1.2 on bottom mix?

To keep the oxygen exposure down to a min for one. The other things is that O2 and N2 are the killers in the dive world...Helium is your friend. No need to spike the O2, use helium to lower the N2.

 

[TheRedHead]

In our class, I think the NOAA, IANTD, and TDI, all gave either 1.3 or 1.4 as max for working portion of the dive and 1.6 as max for deco stops.

You took an IANTD class too? All the questions on the TDI test used 1.6 for the dive. I don't dive at 1.6 because BT is 45 minutes at that PO2.

 

[TheRedHead]

Could you explain this a bit more? I don't understand.

Off the top of my head, NOAA recommends no more than 45 minutes of exposure at 1.6 PO2.

 

[TheRedHead]

To keep the oxygen exposure down to a min for one. The other things is that O2 and N2 are the killers in the dive world...Helium is your friend. No need to spike the O2, use helium to lower the N2.

But, Jeff, Helium requires a lot of additional training from any agency. A GUE rec diver is pretty limited to dives above 100 feet. It would be such a PITA, too, particularly traveling.

 

[PerroneFord]

Ahhh right. I remember that they had recommendations for max time on a specific pp. Thanks for jogging my memory!

 

[PerroneFord]

You took an IANTD class too? All the questions on the TDI test used 1.6 for the dive. I don't dive at 1.6 because BT is 45 minutes at that PO2.

I "officially" took an IANTD class, but the class materials were pretty weak. So my instructor taught out of the IANTD stuff, the TDI stuff, and the NOAA manual. He covered a LOT of ground.