More than "Advanced", but not really "Technical"

[rhwestfall]

except, using the NAUI table approach (and similar to PADI), aren't you are done for the day????? These other methods let you continue on for more dives (should you choose to).

 

[lowviz]

Please show me - I thought I understood NAUI dive tables under Air.
Question? if 36m = 120ft and the dive time is 20 mins - I read the tables as 6 mins for Deco (I round up to 25 mins) why do we go to 44 Mins of Deco?
Any comments would be appreciated.

Your question really highlights the effects of adding conservatism to aggressive recreational dives. So, with no conservatism, I would do the dive that DevonDiver offered as:

71 ft 2 min (microbubble stop)
46 ft 2 min (microbubble stop)
30 ft 1 min hard stop
20 ft 1 min hard stop
15 ft 8 min hard stop

Ignoring my microbubble stops, this is exactly at the edge of 10 min deco on an aggressive profile, on air.


Now we go to what I'm discussing, adding in conservatism:
76 ft 2 min (microbubble stop)
53 ft 2 min (microbubble stop)
30 ft 1 min hard stop
20 ft 1 min hard stop
15 ft 23 min hard stop

So the dive just went from 10 minutes of hang time to 25 minutes of hang (2.5 X) by upping my conservatism to the max. I would just cut back on bottom time for that dive especially as it is rather deep for air. That is the "art" part of it, picking the level of risk that works for you...

 

[Basking Ridge Diver]

Agreed - but I am a single tank 80 AL diver. I plan my dives accordingly and as needed add additional hang time but not more than 10 mins. I don't push the time or the depth on dives.

 

[lowviz]

Another thing to consider is that deco obligations can get interesting for AL 80's on liveabords, three dives a day and one night dive for a week...

 

[Doc Harry]

I'd have no problems with someone doing "recreational" deco divies on a single cylinder if they can tell me that they've calculated their gas requirements for the dive and deco, with contingencies, including an air-sharing deco contingency with their buddy, and they can tell me that their single cylinder contains adequate gas and reserve volume for the planned dive.

But none of these "recreational" deco divers can say that they've made such calculations - can they? Can they even say for what contingencies must they plan?

One "recreational" deco diver even stated that they blindly followed the dive master into deco ("trust me").

As for the original poster - you asked our opinions about "recreational" deco diving. If you don't want to hear the answer, then don't ask the question. Sorry if I ruffled your feathers, but you asked the question.

If what you really wanted was validation for your dangerous practice, then you should have asked for validation from other like-minded people who dive beyond their training without the knowledge and skills to properly execute their dives.

 

[lowviz]

I'd have no problems with someone doing "recreational" deco divies on a single cylinder if they can tell me that they've calculated their gas requirements for the dive and deco, with contingencies, including an air-sharing deco contingency with their buddy, and they can tell me that their single cylinder contains adequate gas and reserve volume for the planned dive..

Well there you have it. Nicely summarized. My question is: How does a recreational diver get these skills in a manner more responsible than gleaning bits from social scuba forums?

... But none of these "recreational" deco divers can say that they've made such calculations - can they? Can they even say for what contingencies must they plan?

One "recreational" deco diver even stated that they blindly followed the dive master into deco ("trust me"). ...

And there is the problem. First one has to actually realize the level of risk that they are assuming. Like children, they expect that they can just try something. Their thinking is: if they get away with it they continue. If they get burned, they can just put it on their "$h!!t not to do again" list. Doesn't work like that in scuba.

I agree, I see a huge lack of awareness in aggressive recreational divers. Thus my original post.

... As for the original poster

That would be me.

... - you asked our opinions about "recreational" deco diving. If you don't want to hear the answer, then don't ask the question. Sorry if I ruffled your feathers, but you asked the question.

I did exactly that, asked for opinions. Sorry if I probed some of those answers, especially the ones that just quote chapter and verse. Recreational divers rarely follow chapter and verse, I was looking for more. BTW, "ruffling my feathers" is in your mind, not mine. I tend to speak directly, most people here know that. I expected heavy "incoming" when I first posted.

... If what you really wanted was validation for your dangerous practice, then you should have asked for validation from other like-minded people who dive beyond their training without the knowledge and skills to properly execute their dives.

First and foremost, that is not how I dive. I have a lot of real technical training and see huge value in applying that training to my recreational dives. I'm convinced that the further one progresses into tech diving, the more conservative one becomes. This thread is an attempt to uncover the unintended consequences of applying both the technical mindset and initial tech skills to rec-only divers.

 

[boulderjohn]

I was doing some research on an older topic in another forum today, and I came across a long post in a thread related to a scuba diving fatality. I thought part of it might be interesting to those who are reading this thread. I have blipped out the names. The one I identify as NAME2 was an open water scuba instructor. I added some explanations in italics and brackets.

A few weeks ago, NAME1 calls me from the hospital, telling me he got bent at the nest! [He is talking about the Eagles Nest dive site, a very challenging and deep site recommended for advanced cave divers only.] I promptly said WTF!!! He told me that HE READ THE INFORMATION ON LINE, and that since he didn't have a trimix cert, he and NAME2 dove air. They planned on decoing on 32% and "cleaning up" on 80% as he put it. He did not use a plan, and was diving off NAME2's VR3 (they were sharing). He also told me that NAME2 called the dive early because of a catastrophic gas failure, in which they were forced to isolate. Due to the loss of gas, they were not able to complete their deco plan.

I was at a loss for words. I pleaded with him to never ever do this again. That they got VERY lucky to make it out, and that they had no business being in there.

Not long after that, NAME1 contacted me about getting advanced Nitrox certified so that he could get his o2 filled. That seemed to be the inherent problem, shops refused to fill their tanks with Trimix or 100% o2 without certs. Knowing that he had only been diving a short while, I asked him why he wanted this class, specially without decompression procedures. He told me he wanted to dive the Nest and Wayne's world! [Wayne's World is another advanced site.] I just about jumped through the phone and told him to never ever go into that system, as he won't make it out. He repeatedly told me that NAME2 was confident as a CAVE DIVER and that he trusted NAME2 to get him out if a problem happened. [NAME2 was not cave certified--he just had introductory certification.] I asked him if he was Cave certified, and he told me he had finished Cavern and was working on Intro with Rich Courtney. I contacted Rich Tuesday night, and he told me that NAME1 never finished cavern due to a strained back. The last time I talked with NAME1, was about 1 week or so ago. He wanted me to take him through Cave 1. I asked him why he didn't continue with Rich, he told me that it was going too slow, and that he NEEDED to get certified. I refused. I told NAME1 that I did not believe he had the proper mindset or attitude to do these dives, with everything going on in his life right now. He told me that NAME2 needed a buddy, and he was going to dive with him. I pleaded with him to come dive a wreck with us, it was free, we have a boat, just show up and let's dive just to dive.

...that was the last time I heard my friend's voice...​

Both NAME1 and NAME2 died in Wayne's World that day. I wonder if during their last breaths they still thought doing the more advanced dives without proper training and certification was a good idea.

 

[lowviz]

Congratulations on a truly superior job of obfuscating the whole point of this thread.

US Navy Dive Table 5 gives me 20 minutes of bottom time at 110 feet on air, Tolten, one of my favorite wreck dives.

My VR3 gives me only 9 minutes on the same dive, same gas, before it puts me into deco. All I'm suggesting is that I can dive aggressive tables within NDL limits using deco procedures and remain "recreational". Obviously, such thinking has no place here. You win.

 

[DevonDiver]

"I can fiddle and manipulate an algorithm so grossly that it'd allow me to do a dive of X duration and Y depth without deco. I know that dive would be potentially damaging and I accept the risk of DCI would be elevated. However, due to that fiddling and manipulation, I can define said dive of X duration and Y depth as a 'recreational' dive.

That dive of X duration and Y depth would be much safer conducted as a technical dive, with an intelligent, staged decompression ascent profile.

Therefore, why can't I do that dive of X duration and Y depth as a technical dive... but because I have 'proved' it possible a recreational dive (albeit one that is lunatic)... I don't think I need technical training to do it. I've got an expensive computer and some extra cylinders. Equipment answers all my needs. Training is irrelevant."

That isn't flexible thinking. It's a sad appeal for someone to affirm and enable a dangerous approach to diving.

 

[lowviz]

"I can fiddle and manipulate an algorithm so grossly that it'd allow me to do a dive of X duration and Y depth without deco.

By this, you obviously mean dive the US Navy Tables.

... don't think I need technical training to do it. I've got an expensive computer and some extra cylinders. Equipment answers all my needs. Training is irrelevant."

Really? Show me where I ever said or implied lack of formal training.

.. That isn't flexible thinking. It's a sad appeal for someone to affirm and enable a dangerous approach to diving.

Uh, that quote was from someone else. You suffer from a profound lack of attention to detail...