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Reconsidering Deep Air?

Discussion in 'Technical Diving' started by CAPTAIN SINBAD, Mar 23, 2021.

  1. rjack321

    rjack321 ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Port Orchard, Washington State
    Where is this place?

    Helium is available in some manner or another even at places like Truk and Bikini. Yes as some point you invest in your own supply bottles and your own compressor and/or booster if you want to dive.
  2. mac64

    mac64 Contributor

    # of Dives: 5,000 - ∞
    Location: Ireland
    DiveClimbRide, couv and OTF like this.
  3. mac64

    mac64 Contributor

    # of Dives: 5,000 - ∞
    Location: Ireland
    I think I’ve said numerous times that people are not the same and need to take personal responsibility for how they dive and what they are comfortable with. And have hugely different levels of experience. I’ve worked deep underwater since I was 17, I’ve manhandled heavy gear underwater. I know how easy it is to get out of breath underwater and how not to. In the seventies we followed the salvage ships working the wrecks along the south Irish coast and would take what they left for scrap. At the time I could get a pound for a light bar and 3 pound for a heavy one. (Brass bars and copper ingots were the main thing we were after) We manhandled the bars into cradles and sent them to the surface. We put explosives under the hull and cutting changes around the shafts and blew the props off and lifted them. We took the spare blades and anything else we could sell. Money and excitement were the motivation, So no narcosis doesn’t bother me and I’ve never given gas density a second thought. Today I service all the local moorings and ground gear, clear foulings, service fishing and angling boats. And any other handy job. When I go out to the wrecks now I nose around at my ease and enjoy the view. I still own the“S.S. Barrister “ she’s on the bottom in 70 metres
  4. OTF

    OTF Coney Island Whitefish Biologist ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: scubaboard
    I'd dive a rebreather.

    And I might try to work out some crazy logistics to import t-bottles of helium.

    Okay, I might dive air a liiiitle deeper than I do here with the luxury of abundant helium, or I might just do fewer deep deco dives, but I wouldn't become a "deep air" diver. There is too much research indicating that it's unsafe. Sure plenty of guys did amazing things in deep wrecks on air before we had modern research and mixed gas, and sure plenty of people continue to dive that way. I still have plenty of respect for those people but it's not for me personally. I am probably a little more risk-averse than other divers; I dive quite conservative GFs, have no problem thumbing dives, etc. Your mileage may vary.

    Also, given all the work required for tech diving, it's is much more enjoyable to have a clear head and good memory during those precious few minutes you get on the wrecks.
  5. johndiver999

    johndiver999 Contributor

    # of Dives: 500 - 999
    Location: Gainesville FL
    I've brought up some 4-ounce lead fishing sinkers from a shipwreck in 100 feet before.

    But seriously, have you dove with a lot of recreational divers in 120 or 160 feet and been able to observe their performance/reaction?

    If your experience is limited primarily to, "professionals and crazies" who routinely (work) and dive deep on air, your perspective might be skewed, because that sort of activity has a tendency to "weed out" the divers who are uncomfortable or ineffective at significant depths on air.

    I still think your position would be strengthened if you acknowledged the differences between 30 and 60 meters.
    mac64 likes this.
  6. Ucarkus

    Ucarkus Contributor

    # of Dives: 1,000 - 2,499
    Location: Berlin, Germany
    I was watching (again) recently, coral diver going beyond 240 feet on air.
    couv likes this.
  7. jlcnuke

    jlcnuke ScubaBoard Sponsor ScubaBoard Sponsor

    # of Dives: 200 - 499
    Location: acworth ga
    Not having a spare $20-30k to spend on a rebreather and getting trained/certified to do CCR trimix at the moment, I'll stick with open circuit for now. As I don't have that money sitting around for such a purpose, you can imagine I probably haven't budgeted for my own trimix capable fill station with booster pumps etc. either at this point. My local deep diving isn't on wrecks, it's in a quarry. Mostly looking for lost gear (found my nephew's mask at 146' a couple summers ago for instance) or just finding what else is sitting in the quarry. With no current, no extra environmental hazards of significance, nothing but calmly diving near the bottom and looking at/for stuff, I personally find there to be a very low risk of an event happening where I'd be dangerously retaining CO2 down there around 150ish feet. To me, with those conditions, it's not worth driving 5 hours to Florida to get trimix fills to come back up north of Atlanta and dive in the quarry.

    Sure, diving that on air isn't something that some people will do, but it's not outside my risk tolerance to do that dive.
    Now, going to the Oriskany and checking out the hangar at ~176', I'll wait to do that dive until after I can use trimix for it as now there are a lot of other factors involved, including effort of swimming against currents of some unknown amount before getting there, almost another atmosphere of pressure, more excitement on the dive, longer planned deco obligation, etc. that change the overall risk scenario of the dive for me to one that I wouldn't be comfortable doing on air.

    Now, if I had already bought a rebreather, already done all the training to be a CCR trimix diver, etc. then I'd probably do the local dives with the rebreather and trimix instead of on air. Why? Well, at that point it would be convenient and not really have a significant change in costs to do the dives, so why not?

    I guess in the end, it all comes down to what the divers are comfortable doing and their personal situation, and that's a personal decision based on their risk tolerance, current level of training, current equipment, etc.. I'd never tell a diver they were "wrong" to not dive to the bottom of my local quarry on air, but I wouldn't tell them they were wrong to do it either if they were trained and equipped for that type of dive by the standards of major training agencies.
    OTF likes this.

    CAPTAIN SINBAD Contributor

    # of Dives: 200 - 499
    Location: Woodbridge VA
    No one can dispute the benefits of Helium but there are many places in the world where it is not available. People there have a choice. They can either wait for a few centuries so that their local economies can develop to the level where Helium becomes as accessible as it is for us or they could understand other ways to mitigate the effects of deep air which may be politically incorrect by the Western safety standards.

    Before the invention of Trimix, it is not that technical divers in the USA were simply waiting for Helium to be invented. Hal Watts, Chatterton and this whole crowd were still deep air diving. Today we understand that there is an element of Narcosis which is not manageable and that we can attribute to Nitrogen. It is going to be there no matter what. But, we also realize that Carbon Dioxide is more Narcotic than Nitrogen and while Gas density is a factor in the production of CO2, there are other manageable factors such as work of breathing and exertion. While gas density is one constant over which we do not have any control, WOB and exertion is what we may be able to control, to some extent. For us living in the US, a few hundred dollars of Helium saves us from having this discussion but try adding two zeros in US dollars to your gas cost and the above thought process starts making so much sense.

    For what it is worth ... I have many friends who dive to 187 feet on air and everyone of them is still alive. I know a much smaller number who went CCR to avoid the dangers of Deep Air. 4 are dead and one came pretty close.
    Lostdiver71, DiveClimbRide and grf88 like this.
  9. grantctobin

    grantctobin ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 500 - 999
    Location: Chicago
    I think some of your points are valid, but they are diluted by the exaggerations above. Please share where in the world helium costs $300/cuft (~10.70/L)?
  10. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
    I too have been to 187 ft on air and survived. This. Means. Nothing.

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