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Second Thoughts About Rebreather Class

Discussion in 'Rebreather Diving' started by ccrprospect, Dec 18, 2019.

  1. Geo7

    Geo7 Angel Fish

    # of Dives: 2,500 - 4,999
    Location: Los Angeles
    I'd suggest the rebreather fearmongering is a positive thing if kept in a balanced perspective. It should not keep people out of this sport, but instead should instill the respect this activity requires.

    What I see here is that the rebreather community is trying to be honest about the risks. And that is a good thing which can't be praised enough. We know that in airplane piloting a little mistake can be fatal. Similar with riding a motorbike or cave diving. The different risk between open water OC diving within traditional limits compared to CCR diving (even shallow) is not obvious to a non-rebreather diver, so I am glad to see at least part of the industry being upfront about it.

    I am sure the traditional agencies now offering "type-R machines" to the masses by telling them this is not tech diving (see the Mk6 brochures for example) have to struggle in order to incorporate the brutal honesty from this thread into their marketing. And I believe the majority of recreational divers do not really want to commit to what it takes to safely dive a CCR, or any deep diving, or any cave diving. These divers just deserve to be told that CCR is a different animal in many respects, including risks, and decide if they want to tech dive, or rather put on a tank with no hassle and enjoy observing nature using the more forgiving OC gear. The openly stated danger has not harmed the cave diving industry. Rather it seems to be thriving, and the cave community does not seem to tolerate any deviance from the rules.

    To paraphrase what the experienced CCR divers here are trying to say: "rebreather diving is safe as long as you remember that it is dangerous" (yup, stole this somewhere).
  2. KenGordon

    KenGordon Rebreather Pilot

    On CCR you have to check your ppo2. On OC you have to check your gas. Deep on OC you under considerable time pressure, especially back gas but also deco gas.

    I am less paranoid when I know I have all the time in the world and if I have to use it I will still have something to breath. I can use rich trimix at depths I wouldn’t on OC, I have best mix whatever the depth, there is no need to be narked.

    The failure modes are more insidious. You do need to be focussed, you do need to be prepared. In particular, I found divining with people likely to need looking after was a problem, they could distract me before getting in, or take up too much attention in the water.

    I REALLY like having plenty of time. You stop worrying about what other people are doing, how far you have got and ‘just 10 bar more’. All that matters is bailout size vs TTS, and for even for medium depths that is a huge advantage.
    Kmart921, Jay, silent running and 3 others like this.
  3. Lt CHEG

    Lt CHEG Nassau Grouper

    # of Dives: 50 - 99
    Location: Rensselaer County, NY
    I’m having some issues with this topic myself. I have an interest in tech diving. I’m not looking to set any records but wreck diving is what interests me the most and I would benefit from the additional depth limit and bottom time that tech training would give me and would allow me access to many more interesting wrecks. Right now, my only 2 bucket list dive sights that I feel I must accomplish in the next 10-15 years are Silfra and the sunken nuclear fleet at Bikini Atoll.

    I’ve talked with the tech instructor that all the other instructors in my area recommend and he seems like a great guy. I think I can learn a lot from him. He even is involved with chartering a trip to Bikini every 2-3 years, currently using the Truk Master. The only problem that I have is he’s a pretty big rebreather guy and he was telling me that beginning in 2020 Truk Master is only going to have rebreather tech options and not open circuit trimix trips. I honestly have almost zero interest in rebreathers and would rather spend $10,000 to $15,000 on gas for a once in a lifetime (for me anyway) trip like Bikini than get into CCR.

    The majority of my diving will remain recreational in nature. I’m not super close to a lot of good tech diving, so almost all of my tech diving will be from weekend type trips that will be taken a few times per season. Since I have no interest in really crazy stuff I think I would be well served by OC type tech training and diving and if it wasn’t for Bikini I wouldn’t even consider CCR. I’m technically handy and like to tinker with some things, do wood working, etc. but diving is one of my main means of relaxation and I don’t want to be spending much time beyond rinsing and cleaning gear and changing batteries after diving. So I don’t think I would get a lot of fun from diving CCR, except for when it was absolutely necessary. I would have to spend a lot of time working on a CCR unit before I could tackle Bikini with a CCR, and while I won’t go so far as to say it would be drudgery, I know that it will take much of the zen away from my diving for relaxation. Also, it’s likely that I wouldn’t dive CCR much if at all again after, so as you can see I have serious reservations.

    So for me, what will ultimately decide whether or not I get into CCR, at least for a while anyway, is whether or not I will be able to get the gas I need to do Bikini Atoll. Anyone else in a similar set of circumstances?
  4. Divectionist

    Divectionist Solo Diver

    # of Dives: I just don't log dives
    Location: Gold Coast, Australia
    use another operator to do Bikini your preferred way?
  5. grantctobin

    grantctobin Solo Diver

    # of Dives: 500 - 999
    Location: Chicago
    I don’t think even Pete can make that happen. If you plan it a full two years in advance and handle getting your own T bottles to the boat, I could see it. As of now, the Helium in the TrukMaster is brought over from the states on a season to season basis and is really only offered to CCR divers. Assuming standard and appropriate gasses for the depths and ninety minute to two hour total run times, the $10K plus gas bill isn’t too far off. This is on top of the $10-15K trip and flight cost.
  6. lermontov

    lermontov Manta Ray

    # of Dives: 500 - 999
    Location: christchurch
    as a recent convert to ccr i read the various post with a smile because all the reasons pros and cons about rebreathers are ones ive wrestled with myself - sure theres plenty more things to have to contend with in diving a ccr but if you look at it from an investment versus return scenario then for me ccr wins hands down
    When i was on OC ccr divers kept telling me with ccr you have lots of time and I know i acknowledged it verbally but until you really start diving with one you dont appreciate how much of a burden that limiting factor OC diving has. Not only the limits of time but the stress of knowing you have limited time. i can assure you that one factor alone has been incredibly liberating and from a diving perspective you will now have doors and diving opportunities opened to you that you wouldn't consider with OC both in terms of bottom time and depth.

    I also look at it this way - I spend ''x' amount of money getting to and from a dive site add the dive boat charter, accommodation. and food etc and alll this add up to a fixed cost
    so work out your $ per minute of diving. with a ccr you can stretch that time y to get far better value for money.

    Now that i have made the jump - i have no regrets others than wishing id done it sooner

    one more thing to add - yes ccr is not for everyone - its fiddly, its more involved and if you dont want to do long deeper technical dives maybe OC is fine but theres a tipping point if your getting to the place where you need to carry more cylinders or stage dives then its an easy choice
    FreeFlyFreak, KenGordon and taimen like this.
  7. uwxplorer

    uwxplorer Rebreather Pilot

    # of Dives: 500 - 999
    Location: Los Angeles
    When saying: you have more time and quit worrying about gas, I hope that everyone keeps in mind that if the rebreather craps out, you are back on OC. So you can't really rack up more deco (not mentioning travel time) than your BO will allow you to do, and most likely in more stressed state than on a plain OC dive throughout. So you need to be a bit more conservative than you would on OC...or have a solid team.
    In crisis situations, and with a functioning unit, not having gas limitation can help relieve some of the stress (and save your butt), but if your unit then dies, you are back in trouble, probably a bigger one than you planned for.
    It's all a question that Inspector Callahan summed up pretty well.
    And that his protagonist answered wisely.
  8. shoredivr

    shoredivr Solo Diver

    # of Dives: 1,000 - 2,499
    Location: Ontario
    Dude, you’re in Rensselaer County NY? You don’t think you’re close to a lot of tech diving?! You are *ONE hour* from the St. Lawrence River with numerous wrecks such as the Jodrey and the JBKing. You have deep wrecks off Kingston and Point Petre in Ontario. You would for certain get lots of use out of a rebreather.

    Here’s the viz right now on the Jodrey, depth here is about 170’. Not my photo, it’s Ryan King’s.


    This charter operator has lots about tech diving in the river.
    Blue Foot Diving | Thousand Islands Diving Charters for Recreational and Technical Divers, Hyperbaric Chamber Sales and Training
  9. broncobowsher

    broncobowsher Solo Diver

    That would be a case of multiple failures. Neglecting bailout time limits and having a bailout worthy issue together.
    What the unlimited gas supply syndrome is about is when something goes wrong, get lost in a wreck, someone is late back to the up line, you get tangled in your own reel. Those problems are there own problem, you don't have the added stress of the pressure gauge dropping like a lead weight. If you have to spend an extra 10 minutes to correct a problem at the bottom, you have the gas to do that extra 40 minutes of deco. Yes, you are going outside the safety of the bail out window, but all you are doing is using your safety reserves. That is what you have the safety reserves for, when something goes wrong. You don't put yourself in harm to protect the safety reserves. On OC you have a few minutes of reserve if you planned it right. You go over, you just know you are going to either run out trying to make your deco or surface screwed. Rebreather, you can typically overstay your dive plan by a very large margin and still be safe. You don't have the "I HAVE to be heading up NOW" panic, you just have the "damn it, I will be an hour late ending this dive, everyone else on the boat is going to be pissed at me, I am going to owe them a case of beer for this, what should I get them?" thoughts. Which would you rather be worried about?
  10. Angelo Farina

    Angelo Farina Marine Scientist

    # of Dives: 1,000 - 2,499
    Location: Parma, ITALY
    But how much deep are those Bikini wrecks?

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