Preparing for Devil's Throat

[cvchief]

why would you be more worried about being bent on air. There is a time limit either way, and if you push the limits of the time limit doing either are or EAN32, the risk is the same.

Sounded to me like he compared 'bent' to O2 toxicity, not 'bent' on air and 'bent' on EAN and their respective bottom times?

 

[nimoh]

Sounded to me like he compared 'bent' to O2 toxicity, not 'bent' on air and 'bent' on EAN and their respective bottom times?

I got that. My point was just that both have depth and time limits that you need to stay within. Why would one be more worrisome than the other?

 

[Mossman]

I got that. My point was just that both have depth and time limits that you need to stay within. Why would one be more worrisome than the other?

Because the dive takes a certain minimum amount of time and the NDC limits are obviously shorter on air.

 

[nimoh]

Because the dive takes a certain minimum amount of time and the NDC limits are obviously shorter on air.

I can see that, basically better tool for the job.

 

[cvchief]

I can see that, basically better tool for the job.

Exactly. And different risks of different degrees, apples and oranges. I think I would choose oranges.

 

[nimoh]

Exactly. And different risks of different degrees, apples and oranges. I think I would choose oranges.

I think I was hung up on the word "worry".

Doing that dive on air would be shorter and probably less enjoyable, but I wouldn't be worried about getting bent any more than on any other dive.

 

[Ron Lee]

why would you be more worried about being bent on air. There is a time limit either way, and if you push the limits of the time limit doing either are or EAN32, the risk is the same.

Personally, the risks of an O2 hit seem far worse than decompression hits. If I bust a deco limit by 10-15 minutes I may have a chance to properly outgas before surfacing and thus not get bent. If I bust an O2 limit by 10-15 minutes I may not be at grave risk of an O2 hit (unknown what the risk is) but the impact at depth may be far worse.

 

[boulderjohn]

Personally, the risks of an O2 hit seem far worse than decompression hits. If I bust a deco limit by 10-15 minutes I may have a chance to properly outgas before surfacing and thus not get bent. If I bust an O2 limit by 10-15 minutes I may not be at grave risk of an O2 hit (unknown what the risk is) but the impact at depth may be far worse.

People with proper training and equipment regularly plan to bust deco limits by 10-15 minutes or more. It is not a big deal for people who are properly trained. On the other hand, no one plans to bust an O2 limit by 10-15 minutes--nobody. That would border on insanity.

So lets put the numbers more in line with what might happen in a regular dive. Although it is not wise to plan to exceed a MOD, dipping below it briefly is extremely unlikely to cause a problem. There is a pretty good safety margin built into the normal limits.

 

[TSandM]

To me, it's pellucidly clear. Survival of seizures underwater is rare as hen's teeth. Survival of DCS is commonplace. I'd rather risk something that can be treated, than something which, if it occurs, will almost certainly be the death of me.

 

[tracydr]

1) you're right, 32% (and less commonly 36% EAN) ARE the standard mixes, mass produced by the one or two giant tank filling 'factories' on the island the vast majority of Cozumel dive ops use. There are a few dive ops with in-house fill operations/compressors that could do custom mixes like 28 % EAN.

2) The large numbers of divers doing Devil's Throat (and other deep sites) without ox-tox issues are ample evidence that the ppO2 'limits' of 1.40 are excessively conservative.

You go ahead and dive the limits of ppO2. Push it everyday if you like. I'll continue to be conservative. That's a game Of roulette I don't want to play,ever.

---------- Post added October 25th, 2013 at 08:59 AM ----------

I got that. My point was just that both have depth and time limits that you need to stay within. Why would one be more worrisome than the other?

I don't know but I'd be a lot more worried about oxygen toxicity, since that's usually not survivable.