Deep Diving on Nitrox question

[k4kafka]

My favorite dive operation on Cozumel (Aldora) routinely takes divers down into "Devil's Throat" using Nitrox 32. I recently dived this site and hit the first bar of deco on my computer. I would have preferred diving "Devil's Throat" using plain-old fashioned AIR, but in order to the keep everyone on the same profile...we had Nitrox.
Any opinions on this....?

 

[KeithG]

A few questions spring to mind:
How deep did you go?
What do you mean by "the first bar of deco"?

 

[Caveeagle]

As long as you stayed within your MOD and did not have any risk of dropping below it, I see no issue here. Did you calculate the same dive profile using 21%? More deco... Right?

 

[northernone]

Recommend MOD (Maximum operating depth) of nitrox 32 @ 1.4atm ppo2 is 110 feet. Seem to be the new industry norm for recreational nitrox use.... 1.6 contingency planning. (Gone, largely, are the days of 1.8)

With throat dumping out at 120-130ft (if I recall) I would be more comfortable with air personally.

A deep nitrox thread should be more entertaining than the recent and ever popular 'deep air' threads.

Anyone for trimix?

Regards,
Cameron

 

[luscioman]

Why would you prefer plain old air over a nitrox blend for a dive that looks to be deeper than 90 feet. Are you even nitrox certified?

 

[northernone]

A few questions spring to mind:
How deep did you go?
What do you mean by "the first bar of deco"?

He's diving the Zoop Novo, and it has a graphic representation of deco obligation if I recall.

Good question on depth. Some operators drop to 140 after existing the throat even.

In preferring air, I'd rather narc then tox personally. (Remember MOD)

 

[gcarter]

Recommend MOD (Maximum operating depth) of nitrox 32 @ 1.4atm ppo2 is 110 feet. Seem to be the new industry norm for recreational nitrox use.... 1.6 contingency planning. (Gone, largely, are the days of 1.8)

With throat dumping out at 120-130ft (if I recall) I would be more comfortable with air personally.

A deep nitrox thread should be more entertaining than the recent and ever popular 'deep air' threads.

Anyone for trimix?

Regards,
Cameron

At that depth, I would happily use 28%. 32% is marginal @1.6/132'

 

[claymore]

You did not die when you took that first breath after you hit 112 feet on 32% Nitrox?

Ox Tox is not just depth dependent. It is time, exertion and possibly temperature dependent. Short exposure at 1.6 is not a "your going to die" if there are not major extenuating circumstances.

 

[northernone]

You did not die when you took that first breath after you hit 112 feet on 32% Nitrox?

Ox Tox is not just depth dependent. It is time, exertion and possibly temperature dependent. Short exposure at 1.6 is not a "your going to die" if there are not major extenuating circumstances.

Thankfully, you're right regarding ox tox. Especially in the case for the o2 rebreather divers on tables doing 10 minute excursions down to 50ft. (2.5 atm ppo2) and we've lived to tell of it.

However, we're talking recreational vacation diving with lovely safety margins built into the dive planning as recommended by the training agencies.

With this in mind, I'd prefer a better margin found in air if available.

Regards,
Cameron

P.s. just realized I painted ppo2 police crosshairs on me mentioning military tables and dive conditions.

 

[Streydog]

Just curious of the details of your dive: max depth, total time, etc. I am new and learning, Have 40 + dives with Aldora over the last 9 months. The last two trips I dove nitrox after being certified locally. I haven't dove Devils throat but last trip did Maracaibo and Punta Sur for the first time. Max depth at Maracaibo was 110' on 32%, just under 1.4. Punta Sur, sur was the next day and we maxed out at 90'. What did you think of Devils throat?