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The normalization of dives to 100 meters and beyond

Discussion in 'Rebreather Diving' started by 2airishuman, Jul 2, 2019.

  1. 2airishuman

    2airishuman Solo Diver

    # of Dives: 100 - 199
    Location: Greater Minnesota
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    Somewhere along the line, dives to 100 meters (330 feet) became normal dives that reasonable people might choose to make, with proper training and equipment. Some divers accustomed to such dives have gone so far as to characterize them as "like a stroll in the park, really."

    Today, these are apparently the sort of dives that a married couple who are both accomplished divers might reasonably choose to make.

    There have been several fatalities a year on dives to these depths.

    I understand that no agency offers training for dives beyond 100 meters, but there are master classes offered by individual instructors that include 150 meter dives, or even 200 meter dives..

    I offer these questions for discussion:

    1. The depth at which it is considered safe to dive for enjoyment (rather than in pursuit of commercial, scientific, or military objectives) has been made greater over the years. Unlike air dives, which are limited by narcosis, or normoxic trimix dives, which are limited by ppo2, there is no particular depth at which a hypoxic trimix dive becomes impractical (until HPNS becomes a limiting factor at far greater depths than are now being dived regularly). Rather, there is a continuum of incremental difficulty and risk as depth increases; and there are incrementally greater demands on equipment. Where will this end? Will we have PADI Tech 500 with a unit on safe practices for hydrogen blending? Is this a good thing?

    2. At what point does the standard of care for sufficient surface support include having a chamber on site? It has been pointed out in A&I threads that any commercial diving operation to 300 feet would not be conducted without ready access to a chamber.

    3. OSHA has not shown much interest in dive instruction. Dive instruction at recreational depths (38 meters/130 feet max) has historically been very safe. As the depths to which technical diving students are taken increase, this may no longer be the case. Could the industry as a whole be inviting unwanted regulatory attention by training divers for ever-greater depths?

    4. How does the thinking diver characterize these dives in discussion with non-divers? Given what we know today, and the training available today, can 100 meter/330 foot dives be conducted safely? Do we talk about accidents at these depths as being isolated incidents that could happen to anyone, or should these be characterized as risky activities that most divers don't condone? Is 330 feet the new 130 feet, or is there some other limit now?

    5. Has it become acceptable to pursue depth for its own sake? In OWD and AOW classwork, as far as I know from all agencies, students are told not to pursue deep dives just for the sake of depth -- but rather to use the ability to dive deeper to allow them to pursue other dive objectives that require it. For those of you who make regular hypoxic trimix dives, have your deeper dives opened up a new world for you that you could not otherwise visit? Or is it just something that is satisfying because of its difficulty?
     
    markmud, Chidiver1, AfterDark and 5 others like this.
  2. chrisch

    chrisch Solo Diver

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    The increase in depth reflects the development of technology. Just as helium increased the range of open circuit diving, rebreathers increase the ability of divers to explore deeper sites. It is in the nature of humans to push the envelope, we seek out the limits and then what is "safe" what is not at the limits moves with the extreme. Cave diving is a very good example - what was once an "extreme" dive is now a training dive. Neither deep rebreather divers nor cave divers are dropping dead in huge numbers.

    It is unlikely in my view that the dive community will see a major leap forward in technology in the short term. The next 20 years or so are more likely to be concerned with climate issues and a re-evaluation of what we do for leisure and it's impact on the planet. Either that or space tourism will become the big new thing and the thrill seekers will head off in the other direction to the world's oceans. How long we survive as a species then is anyone's guess.

    What will limit underwater exploration is our physiology. The need to rid the body of absorbed gas is the factor which is most limiting. A couple of hours decompression is tedious and much more than that is beyond the point most normal people find diving unrewarding on the cost-benefit analysis. At some point it becomes more intelligent to go and view the deep ocean wrecks in a submersible than in a drysuit.

    If we can overcome the climate problems (let's hope so) maybe our grandchildren will be able to go and see deep ocean wrecks like we go to the aquarium today. That wonderful future is one worth fighting for but right now we are looking more at Mad Max unfortunately.
     
    Khrissi, rjack321 and RyanT like this.
  3. cathal

    cathal Nassau Grouper

    # of Dives: 500 - 999
    Location: Ireland
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    Just curious what is your definition or interpretation of the word ‘safely’ in this point?
     
  4. Miyaru

    Miyaru Tech Instructor

    # of Dives: 2,500 - 4,999
    Location: EU
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    Technology and decompression knowledge have advanced a lot over the last two decades. These developments have added to the general safety of deeper dives in terms of equipment reliability and a better handling of decompression stress.

    On the other hand, all these developments and insights have never been a replacement for the required skills and mindset that a diver needs to conduct such dives. With more people diving regularly beyond the max. course depths, the appeal to do so as well becomes bigger. In this topic you can see a diver eager to go this deep, but he has mastered none of the required skills and the required mindset was probably forgotten when he packed his holiday bags.

    Tarek aborted that dive - too late according to the local diving community, but when somebody shows a trimix card and pays for all gasses, when do you abort? That discussion is for the other topic, but this video illustrates the kind of divers that buy their way beyond recreational depths. There will be more...

    The two masterclasses that you linked to are certainly not aimed at such divers. Ben requires full cave, full trimix and experience as a prerequisite, Ahmed will likely require similar credentials, although not mentioned on his page.

    As for the limits.....OC will be limited by the amount of gas needed and the helium costs. That limit will probably be reached way before the technology limit. CC allows deeper depths and farther exploration, and technology limits have been reached (imploded scooters and computers), although developments have overcome these limits soon after.

    As for the other points:

    Commercial divers can be left out of the equation. At these depths, it's all saturation diving.
    The equation with the thinking diver at OWD/AOW level doesn't work either - recreational divers are taught to stay within NDL limits and above 130ft/40m. The next level training to dive beyond these limits do not just teach skills and procedures, but also focusses a lot on the required mindset for a technical diver.
    Once a diver has mastered all these requirements, the boundary between normoxic and hypoxic depths can be reached safely. Where safely is determined by the mindset of the diver, not the equipment.
    Crossing that normoxic/hypoxic boundary requires you to already have the mindset and skills required for 330ft/100m, even it it takes several (course-)dives to reach that depth. And it takes a lot of experience / diving to get safely to that point.

    Is 330 feet the new 130 feet, or is there some other limit now? - certainly not. Recreational divers bouncing to such depths on a single tank are simply f#cktards risking their life, with a mindset opposite to technical divers. The last dive is always a single-way trip.
     
  5. beester

    beester DIR Practitioner

    # of Dives: 1,000 - 2,499
    Location: Belgium / Italy
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    You are right... A comparison of the 10 deepest wreck dives in the 90s vs now by Mike Menduno.

    Extending The Envelope Revisited: Correcting The Record of the 30 Deepest Tech Shipwreck Dives

    I think 100m is the new 60m (depth at which you normally would use hypoxic mixes). I can't answer any of your questions but for sure technology is playing a big part in this evolution. Technologically speaking the 3 main tools that have made this leap possible are:

    - Dive computers (becoming much more reliable)
    - Rebreathers
    - DPVs

    Diving to 100m on OC with a reasonable bottom time (no bounce dives, but let's say 20-30 min BT) safely requires a lot of logistics, a lot of equipment stress (very big backmounted tanks, and a lot of stages), good underwater skills (gas switches, tank rotations, communication, ascend), good understanding of decompression and execution of it,a lot of underwater teamwork, etc.

    Diving a rebreather makes life easier, specially if you use more risky bail out strategies (team bailout). In an sense a monkey can fly an eCCR, as long as everything goes ok. Also the need for a good dive team, buddies is less needed, because you (should) are able to solve more fault scenarios on your own on a rebreather. So you can go from nothing to very extreme dives in a very short time span. Extreme doesn't only mean deep, it could also be long, doing a 1 h bt 60m dive is more extreme than a 20' BT time 90m dive.

    Same with cave diving, where it's not only rebreather but also DPVs that fasttrack cave penetration.

    My background is partially in a very conservative agency (GUE), but even there you see individual divers moving fast!

    For me personally depth in itself has no value, it's what's there that has value. I've got a background in history, been interested in it all my life. I love participating in underwater projects, involving divers, scientists... I've done this on shallow wrecks (for example a 30-35m north sea wreck: Westhinder ) but also on deep wrecks, sites. It's not about deeper diving... it's about being able to document what you find, and in this regard technology has as well taken giant leaps (camera's, video, 3d photogrammetry)... and my personal goal (and the reason I'm started diving rebreather) is to expand this and dive more on these projects as a volunteer.

    Regarding risk, I've always been quite slow in taking next steps. My first trimix dives were in 2010, and I only moved on beyond the 50-55m range in 2016... I've reevaluated since I've become a dad, but in the end diving is what really makes me happy, my girlfriend is a mountaineer, so she understands this.
     
    rjack321 and chrisch like this.
  6. Nathan Doty

    Nathan Doty Barracuda

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    I used to be a cop, skydive, teach rock climbing... Now I have kids :)
     
    Khrissi, markmud, John Bantin and 2 others like this.
  7. HKGuns

    HKGuns Nassau Grouper

    # of Dives: 0 - 24
    Location: Merica
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    I only recently started to pursue this activity. Being on the long side of 50, about the only thing I can add is a bit of an outside perspective.

    I’m literally shocked by the seemingly regular number of deaths, of “experienced” and reknown divers I’ve read about since joining this site a very short time ago. I find it quite sobering.

    I suspect nothing will change, as I sense there is an under appreciation of the potential dangers, regardless of experience. Combine that with a dose of over confidence and you probably are in a dangerous state.

    I plan to do this for fun and I find going deep pretty intimidating. But I also understand there is likely a progression I have yet to experience.

    Perhaps the dive community needs to take a stronger stand against taking such risks?

    At the end of the day I suppose if you take the risk, you live with the consequences.

    Sorry to intrude, but sometimes an outside view is worth something, probably not in this case.
     
  8. hroark2112

    hroark2112 Tech Instructor

    # of Dives: 0 - 24
    Location: Raleigh, NC
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    When I did my hypoxic cert dives, the last dive included a deep bailout drill from CCR to OC. Gas goes really fast at those depths. You can watch the pressure drop as you take a breath. That's an expensive breath when you're breathing 60% helium. I sincerely doubt 330' will become any kind of norm for the average diver. I'd love to know the stats on how many divers hit 330', I doubt even .1% of divers even approach 200'.

    OSHA won't be getting involved in recreational diving. They just don't have the jurisdiction to get into it.
     
    cathal likes this.
  9. Storker

    Storker Divemaster

    # of Dives: 100 - 199
    Location: close to a Hell which occasionally freezes over
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    Normalization of deviance is quite often the root cause for accidents and fatalities. It takes diligence to avoid going there.

    Professionalism/Diane Vaughan and the normalization of deviance - Wikibooks, open books for an open world

     
    markmud, Barnaby'sDad, HKGuns and 2 others like this.
  10. AfterDark

    AfterDark Solo Diver

    # of Dives: 500 - 999
    Location: Rhode Island, USA
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    I started diving when the Andrea Doria was called the Mt Everest of "sport diving". Dives were usually air only with minimum surface support and certainly no voice comm between diver and surface or diver to diver. More than a few divers were lost and still are on the Doria but, it can no longer be considered as the MT Everest of "sport diving".

    However can diving the Doira with all the latest technology and training be considered safe? Penetration aside, my understanding is there isn't much left to penetrate anyway these days. IMO no, it's still 240FSW and a lot can go wrong.

    I get pushing the envelope, humans have been doing that since day one but IMO the more extreme envelope pushing in this case should have equal safety consideration such as the aforementioned chamber, medical support, stand by divers, and communications. Mindset is important but, sometimes things happen beyond the control of any one person no matter how cool under pressure one might be. Apollo 13 pushed the envelope, failed their mission due to equipment failure but came back alive due to the amount of support to help them and of course their presence of mind and mindset. However mindset alone would not have saved them.

    As divers we seek to stay alive in a hostile environment for our recreation, sometimes crossing the line into territory that is beyond recreation but still telling ourselves it is recreation without adequate support. Boat crews just looking over the side waiting for overdue divers from 300FSW is foolhardy of the divers for being in the situation, IMO.
     
    markmud and Bob DBF like this.

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