Deep diving advice that goes against conventional thought?

[Akimbo]

This "Compression Arthralgia" is something I have never experienced, even on dives when I had high workloads at 280 feet --on air or trimix...

Fortunately, I have never experienced it either, but know several divers that weren’t so fortunate including my brother. I have read that symptoms can occur between 100'/30M and 200'/60M. The shallowest I have personally heard directly from another diver is around 350'. It isn’t clear to me that 30'/minute is any better than 200'/minute. All my sats used 60'/hour or 1'/minute and I won’t dive deeper than 330'/100M surface-supplied for [-]unrelated[/-] lots of reasons.

My brother’s dive resulted from a time-critical problem where four divers were blown-down to around 600' in 20 minutes or 30'/minute. They could barely climb the ladder into the bell. It took about 12 hours to recover though minor pains lasted for days. All four were in their mid-20s and found a new empathy for people afflicted with arthritis.

 

[DCBC]

This "Compression Arthralgia" is something I have never experienced, even on dives when I had high workloads at 280 feet --on air or trimix.
Wondering why it appears in some divers and not in others. I do think this is why some deep divers use scooters, so the effects of this are less significant in performing the dive....and maybe less exacerbated--as I have heard some divers say they feel better after the dive if they do less work on it...again, I don't experience this, so it is alien to me.

I'm getting confused here of where to post this? I had added this information to the Exley thread. Monitor please erase as appropriate.

Regarding Hyperbaric Arthralgia, I've experienced this in the form of a dry grainy feeling in the joints (when they are used). A popping of the joints also occurs; which increases with depth and changes from discomfort to mild/moderate pain on dives over 800 FSW. I'd estimate about 50% of divers experience this below 500 FSW (to a greater or lesser degree). On dives below 1000 FSW virtually every diver I'm aware has had this experience.

HA does dissipate. Generally speaking, the deeper the dive, the more severe the symptoms and the longer that discomfort/pain can be expected. Symptoms are also delayed in that they may start at 500 FSW and keep getting worse after you've stopped at a deeper depth. This will stabilize and disappear after a number of hours (or couple of days). Again, no pain or discomfort is experienced if there's no movement. The wrist, shoulder, knee and hip are the areas most commonly affected. Because of the nature of Hyperbaric Arthralgia, I doubt that this was a factor for Sheck.

 

[Akimbo]

... The wrist, shoulder, knee and hip are the areas most commonly affected. Because of the nature of Hyperbaric Arthralgia, I doubt that this was a factor for Sheck.

I understand that the US Navy first got interested in compression pains as a result of submarine escape experiments. They used super-fast compression rates in the hope of minimizing DCS and Narcosis complications. I believe that is where the symptoms showing up between 100 and 200' came from.

I also doubt that it is a factor in accidents with experienced deep divers. However, I’m not ready to dismiss it as a factor in some deaths where the diver was sucked down or badly mismanaged their buoyancy though. I understand it can be pretty debilitating.

Though they are very experienced, I wonder if some of these super-deep freedivers are aware of it? On the other hand, they may be so Narc’ed and in their “Zen” state that it is just background noise.

 

[DCBC]

It's reasonable to believe that the cost of Helium will skyrocket as the World's Helium supplies dwindle over the next few years. Do you think more Divers will turn to Deep-air? or will they simply limit their diving to depths less than 50 FSW, to insure that they are not 'diving under the influence?'

 

[tomfcrist]

It's reasonable to believe that the cost of Helium will skyrocket as the World's Helium supplies dwindle over the next few years. Do you think more Divers will turn to Deep-air? or will they simply limit their diving to depths less than 50 FSW, to insure that they are not 'diving under the influence?'

If it gets that much more expensive, I would assume the former.

 

[kr2y5]

It's reasonable to believe that the cost of Helium will skyrocket as the World's Helium supplies dwindle over the next few years. Do you think more Divers will turn to Deep-air? or will they simply limit their diving to depths less than 50 FSW, to insure that they are not 'diving under the influence?'

Or upgrade to a rebreather... some ~$10K models already have built-in CO2 sensors, hopefully in a few years the technology will mature and the price will drop.

 

[DCBC]

Or upgrade to a rebreather... some ~$10K models already have built-in CO2 sensors, hopefully in a few years the technology will mature and the price will drop.

CCRs will first have to developed to a point where they don't have to be piloted. No doubt it's a matter of time before everyone goes to closed-circuit. Looking at how the diving training cycle has changed over the last 50 years, the next 50 will have non-divers using CCR after a 4 hour course.

 

[Reg Braithwaite]

No doubt it's a matter of time before everyone goes to closed-circuit. Looking at how the diving training cycle has changed over the last 50 years, the next 50 will have non-divers using CCR after a 4 hour course.

Pardon my trolling, but I think it's ridiculous that people freak out at the dangers of diving CCRs, but then climb into a motor-car and drive it down highways while checking their email and rocking out to "Stairway to Heaven." With their kids in the back seat.

We as a society have an amazing tolerance for the lethality of automobile driving. If we were to take the same attitude to CCRs, then yes, everyone will pilot their own CCRs. At the very least, they aren't going to drown other divers.

;-)

 

[danvolker]

Pardon my trolling, but I think it's ridiculous that people freak out at the dangers of diving CCRs, but then climb into a motor-car and drive it down highways while checking their email and rocking out to "Stairway to Heaven." With their kids in the back seat.

We as a society have an amazing tolerance for the lethality of automobile driving. If we were to take the same attitude to CCRs, then yes, everyone will pilot their own CCRs. At the very least, they aren't going to drown other divers.

;-)

If you want to use the family car analogy, that might be fair if you add the new "Auto-Pilot" feature that is not quite perfected yet, and have the driver of the car on the interstate , napping because the auto-pilot is driving..... As long as it works, it is awesome ( just like the CCR)...if suddenly it stops working, and the "driver" is not paying attention....a serious accident is the going to result.

Open circuit has no auto-pilot, and is so simple, even a PADI OW diver can do it

 

[Reg Braithwaite]

if suddenly it stops working, and the "driver" is not paying attention....a serious accident is the going to result.

We can theorize all day that it is safer to have a system where you have to pay attention all of the time, but the evidence is overwhelming that even with a system (driving a car) where a moment's inattention can kill, people can and do kill themselves and others regularly. In the United States, 15.5 people die in motor vehicle accidents annually per 100,000 population.

Now, I am not saying this is a bad thing per se, obviously people feel that this is an acceptable risk, and who am I to argue against it?

All I am saying is that this is evidence that if people want a certain kind of experience or freedom, they are certainly willing to put up with a non-trivial risk of death by misadventure, so it's not impossible to imagine that one day, rebreathers become commonplace.