Insight to Henleys Castle

[Sludge]

A few thoughts:

I've done deep air - 192' in Bonaire. The conditions were perfect - 82° water, 100' vis, a beautiful shipwreck (the windjammer). A seven-minute bottom time (according to two computers) felt like thirty seconds. I can only imagine what would have happened had something gone awry.

A guy on Bonaire told us why he always dived it on air: (insert thick French accent) "A dive to 200' on air is like enjoying a bottle of fine wine with good friends." Sure, but don't think you're okay to drive home afterward. You're drunk.

As far as nitrox goes, it's becoming accepted that oxygen is as narcotic as nitrogen. I've made enough dives to 100' on EAN32 that I think it's exactly as narcotic as air. Reactions that are instantaneous at 30' take a few seconds at 100'. At 150'? I'm sure much slower.

{Free advice alert - no liability assumed} If you're all that concerned about the cost of a trimix course, all the information you need to dive trimix is on the internet for free. I'd bet you'd be safer gathering this info yourself and diving trimix than taking air to Hendley's Castle. {Alert over}

[LiteHedded]

air is for tires.

[KarsticGator]

That happens when you don't sign your name to your posts...

Oh... sorry. Should I attach my resume as well? Or how about an advertisement for my business?

Adam Smith, MBA
CEO - Mix is for Sissies, Inc.
Call 800-NARCOSIS, for all your deep air diving needs.

[DA Aquamaster]

nobody said it was. it doesn't cure stupid but it helps...

I agree it helps an individual diver, but that's only part of the potential problem in setting solid END limits.

For example lets take the "average" cave diver has an "average" IQ. The mean IQ is 100 and the standard deviation for most IQ scores is about 15 points, so the "average" range for IQ is 85 to 115 and about 2/3rds of the population will fall within that range - with half of them being below 100 and half of them being above 100, but all of them considered (broadly) to be of "average" intelligence.

The point being a diver on the low end of that range is potentially 30 points behind a diver at the upper end of that range in terms of overall cognitive functioning even before we descend. Various subtest scores involving such things as spatial relations or numeric operations will have similar variation so the total picture is a bit more complicated, but you get the idea.

Do we want to have a different END based on surface cognitive functioning? Of course not - as the average diver probably does not know where they fall in temrs of general IQ let alone in subtest performance. But the first point is that most divers potentially have the ability to make informed decisions about the depth and conditions at which the really need a reduction in narcosis to function effectively and that makes more sense than relying on a flat 100' END.

The second point is that if a diver happens to be one with an 85 IQ, he or she is already challenged at the start of the dive and while helium might help limit the additional impiarment that results, it may not help him or her enough to "catch up" at the 100-150' depths we are talking about here.

The concern is what happens when the use of helium breeds over confidence because the person is using helium. At best, they are no better than they are on their best day at 10' and for some, that is just not all that great.

[icestac]

Did L.O.G. on air 3 weeks ago. Hit 165. Narcosis was not an issue.

Congratulations. I am glad you made it back safely. I would choose not to do that dive with you.

Oh... sorry. Should I attach my resume as well? Or how about an advertisement for my business?

Adam Smith, MBA
CEO - Mix is for Sissies, Inc.
Call 800-NARCOSIS, for all your deep air diving needs.

It is courtesy to introduce yourself so you don't look like a troll when making controversial comments.

All the best,
Jeff

[jj1987]

Oh... sorry. Should I attach my resume as well? Or how about an advertisement for my business?

Adam Smith, MBA
CEO - Mix is for Sissies, Inc.
Call 800-NARCOSIS, for all your deep air diving needs.

Sorry, I like to know who I'm talking to, even on a forum. Didn't realize it would offend you.

I agree it helps an individual diver, but that's only part of the potential problem in setting solid END limits.

For example lets take the "average" cave diver has an "average" IQ. The mean IQ is 100 and the standard deviation for most IQ scores is about 15 points, so the "average" range for IQ is 85 to 115 and about 2/3rds of the population will fall within that range - with half of them being below 100 and half of them being above 100, but all of them considered (broadly) to be of "average" intelligence.

The point being a diver on the low end of that range is potentially 30 points behind a diver at the upper end of that range in terms of overall cognitive functioning even before we descend. Various subtest scores involving such things as spatial relations or numeric operations will have similar variation so the total picture is a bit more complicated, but you get the idea.

Do we want to have a different END based on surface cognitive functioning? Of course not - as the average diver probably does not know where they fall in temrs of general IQ let alone in subtest performance. But the first point is that most divers potentially have the ability to make informed decisions about the depth and conditions at which the really need a reduction in narcosis to function effectively and that makes more sense than relying on a flat 100' END.

The second point is that if a diver happens to be one with an 85 IQ, he or she is already challenged at the start of the dive and while helium might help limit the additional impiarment that results, it may not help him or her enough to "catch up" at the 100-150' depths we are talking about here.

The concern is what happens when the use of helium breeds over confidence because the person is using helium. At best, they are no better than they are on their best day at 10' and for some, that is just not all that great.

I see your point, but it just confuses me on how someone goes from bringing a pony bottle to do the grand traverse, to being OK diving to 150ft on air across the the slough.

[AB8CD]

A guy on Bonaire told us why he always dived it on air: (insert thick French accent) "A dive to 200' on air is like enjoying a bottle of fine wine with good friends." Sure, but don't think you're okay to drive home afterward. You're drunk.

It had better be a BIG bottle (or very few friends)!

As a police officer I have had the curious experience of drinking with others and measuring blood alcohol levels. It is amazing how different people respond to similar amounts of consumption.

My point is that what is acceptable (safe) behavior for one physiology may not be for another. I have no problem acting more conservatively than necessary (so as not to lead one astray...) but it doesn't mean that I could not have responsibly pushed the limits a bit farther and remained well within my own established guidelines of safety.

[KarsticGator]

Congratulations. I am glad you made it back safely. I would choose not to do that dive with you.

It is courtesy to introduce yourself so you don't look like a troll when making controversial comments.

All the best,
Jeff

Jeff,

In all fairness, I wouldn't have asked you to make that dive with me. I don't know you, or your diving abilities. But you have now cleared up any confusion... just in case I had some reason in the future, to ask you to dive.

As for introductions, I first created a profile on this forum back in 2000. I took several years off to focus on "dry", and vertical caving, and unfortunately didn't do a lot of diving. (I forgot my old log-in info, and created a new name.)

However, I am reminded one reason why it was so easy to allow another realm of caving take precedent of my time... it's the people involved in the sport. Sure, there are super ego's in every facet of caving. But the relative number of them in cave diving is quite high. And one thing that I will never understand is why some cave divers eagerly say the way you choose to dive is "wrong" or "stupid"... and then try to cloak those comments as concerns for your safety, or for the threat of losing site access.

I truly wish more people in the cave diving community would be more open, and take the mindset of what works for some people, might not work for others. This concept is much more apparent in the "dry" caving community. And I recall similar debates years ago, between different styles of equipment configuration, and certification agencies. But at the end of the day, we are all cavers who choose to dive with certain people, using specific criteria, within our level of comfort. There is no need to call someone a moron because you don't agree with what they practice.

For some reason I thought the frequency of over-inflated ego's had declined since the late 90's. How I was mistaken.

Adam

[KarsticGator]

Sorry, I like to know who I'm talking to, even on a forum. Didn't realize it would offend you.

None taken! Thanks for helping me out with the forum etiquette.

[sskasser]

It had better be a BIG bottle (or very few friends)!

As a police officer I have had the curious experience of drinking with others and measuring blood alcohol levels. It is amazing how different people respond to similar amounts of consumption.

My point is that what is acceptable (safe) behavior for one physiology may not be for another. I have no problem acting more conservatively than necessary (so as not to lead one astray...) but it doesn't mean that I could not have responsibly pushed the limits a bit farther and remained well within my own established guidelines of safety.

Excellent point! Hard and fast numbers don't apply to the human body in most cases (that 98.6F thing still puzzles me!). One person can have a single drink and be obviously impaired, while another with very similar phyiscal characteristics would not be.

The same happens with narcosis. I've seen big, strong, competent divers that were plumb loopy at ENDs of 80 (granted it was in a dark, soupy mess). I've watched others I wouldn't have believed pass "competency" tests with ease at much deeper ENDs.

Guidelines are a great starting point, but please listen to your body and "gut", and be self-aware. If it don't feel right, chances are it's not. Don't let ego pressure you into an END that isn't right for you, regardless of what the "standard" is. And don't feel compelled to force others to adhere to your beliefs on what's the "right" END. Their MMV