Backing off from technical diving

[TSandM]

30 minutes BT at 100' using 32% EAN as air. This gives a 16 minute theoretical obligation: 6minutes @ 20', 10 minutes at 10'.

That's very interesting. The NDL table that I use gives 30 minutes at 100 feet on 32% as the min-deco limit -- that means 5 minutes of deco, one at 50, one at 40, one at 30, etc.

 

[GrandpaScuba]

The rise in technical diving has provided the diving community with more flexible equipment and some alternative ways of looking at diving situations. Some of the equipment that I have is considered "technical" equipment. I bought it because it allowed me to make desired customizations that regular recreational equipment wouldn't accomodate. However, truth be told, when I go on a diving vacation, I just want nice warm water and pretty fishes. I'm there to relax.

 

[MXGratefulDiver]

Depends on which agency you train with, some agencies still require that you learn to recover a diver from the bottom during OW training.
I think it's SDI but I'm not positive.

NAUI does ...

... Bob (Grateful Diver)

 

[tracydr]

That's very interesting. The NDL table that I use gives 30 minutes at 100 feet on 32% as the min-deco limit -- that means 5 minutes of deco, one at 50, one at 40, one at 30, etc.

I'm confused. He said it was NDL and gave no deco obligation but also said it gave a 16 minute theoretical obligation. And, you're also saying it gives an obligation.
Either way, it appears that 30 minutes at 100 feet is giving you a ceiling. Appears a little risky for the non-tech trained beginner to be playing around with this by themselves.

 

[LiteHedded]

the way i understood it he was pretending it was air but actually diving 32%

 

[boulderjohn]

Why use a computer to plan your first deco dives. Get a set of tables. Cut a conservative plan. Here's one of the first ones I did using DCIEM tables:
30 minutes BT at 100' using 32% EAN as air. This gives a 16 minute theoretical obligation: 6minutes @ 20', 10 minutes at 10'.

That's very interesting. The NDL table that I use gives 30 minutes at 100 feet on 32% as the min-deco limit -- that means 5 minutes of deco, one at 50, one at 40, one at 30, etc.

I'm confused. He said it was NDL and gave no deco obligation but also said it gave a 16 minute theoretical obligation. And, you're also saying it gives an obligation.
Either way, it appears that 30 minutes at 100 feet is giving you a ceiling. Appears a little risky for the non-tech trained beginner to be playing around with this by themselves.

What you see reflected here is several different approaches to ascents. The DCIEM tables (which I don't have) are different from the Min Deco system TSandM is quoting, which is different from other systems. For example, a 30 minute dive to 100 feet on EANx 32 is a NDL dive on the PADI tables, calling for nothing more than a 3 minute safety stop.

What Dale says is that you can do simple deco dives on your own without taking a course for it. Yes, you can. If you go into other threads in the cave diving forums, you will find OW divers asserting that they can go into caves and come out alive. Yes, they can. People do penetrations of wrecks like the Spiegel Grove and insist that they can come out just fine. Yes, they can.

But sometimes they can't. Sometimes something goes wrong on their planned deeper dive with basic decompression obligations, and they don't have the skill or resources to deal with it. Ask Opal Cohen about that--oh, that's right. You can't. Sometimes OW divers go into caves for just a quick look see, try to exit, and get confused about which tunnel leads out. Ask the guy who got lost in the Catacombs at Ginnie Springs last year--oh, that's right. You can't. Sometimes people get turned around inside a wreck and get confused about the exit direction. Ask the three guys who got confused in the Spiegel Grove two years ago--oh, that's right. You can't.

As others have pointed out, the vast majority of time spent in technical training is devoted to preventing things from going wrong and taking care of business when they do. If nothing goes wrong, that training is unnecessary. You just have to ask yourself how lucky you feel that day.

 

[geoff w]

A dive buddy who is enamored with becoming a tech diver just posted a link to Doppler's blog entry on tech diving rules and complacency, which really hits home on a lot of the comments here so far. You can read it at The Rules Apply to All of Us | Doppler's Tech Diving Blog There's certainly no substitute for quality training for any scuba activity, and especially for tech diving where the risks are magnified relative to recreational diving

 

[DaleC]

Sigh.. heavy sigh. I won't even address most issues. My point was that doing simple deco "lite" dives without undue risk is one way to decide if tech diving is something that actually appeals to you - before running out and dropping thousands on courses and equipment. But hey, misconstrue my words all you want. SB is famous for posters picking only the bits that justify their own preconceptions.

And yes, Litehedded got it right. Just like your instructor simulates a failure scenario but both of you really know he's not actually going to kill you. Not such a crazy concept.

"What Dale says is that you can do simple deco dives on your own without taking a course for it. Yes, you can. If you go into other threads in the cave diving forums, you will find OW divers asserting that they can go into caves and come out alive. Yes, they can. People do penetrations of wrecks like the Spiegel Grove and insist that they can come out just fine. Yes, they can."

Let's not be dramatic John. What I said was more akin to suggesting someone could go cavern diving without taking a cave course, to see if that sort of thing appealed to them. IF it did, and they wanted to go further, then they could take training based on an informed opinion.
If one really looks at my posts, one would see that, rather than encourage new divers to go out and take unreasonable risks, I advocate OW divers spending a lot longer refining skills at the rec level and slowly working into deco diving. In fact, almost everything I post on SB follows the theme of doing simple dives to develop basic skills. I also believe that, if divers did this, they would encounter and adjust to many of the boogeymen being presented as barriers. The reason some may see these as such is that most divers don't spend long enough doing basic dives and accruing experience so they need an instructor to present such scenarios to them.

Honestly; Air diving is not the matrix, and you don't need an oracle to negotiate it.

Lynne, I like the DCIEM tables because I understand how they were derived, that's all. If I learned min deco I would probably use that.

 

[DevonDiver]

Let's not be dramatic John. What I said was more akin to suggesting someone could go cavern diving without taking a cave course, to see if that sort of thing appealed to them. IF it did, and they wanted to go further, then they could take training based on an informed opinion.

Dale, I might still be misinterpreting what you're writing, but... why couldn't those people simply take a Cavern Diver course? Or, as per this thread, take an 'Intro-To-Tech' course... or something like Fundies? The purpose of those 'courses' or 'experiences' is intended to give people a safe and realistic introduction to the demands, standards...and most importantly, mindset of technical diving.

This "D.I.Y. Introduce Yourself To Tech-Lite" malarky seems to be based upon nothing more than the desire to save a buck. Compromise is not the best route into safe technical diving.

Honestly; Air diving is not the matrix, and you don't need an oracle to negotiate it.

You seem to have little empathy or understanding for the needs of developing divers. I would guess that's because you have never taught divers yourself. Whilst you acknowledge that training is "critical" at levels which represent your threshold/comfort zone, you deny the need for it for others at their threshold/comfort zone.

Have you always felt that way? Have you noticed that your disdain for necessary training rose in line with your accomplishments?

 

[DaleC]

Andy, read it any way you want. As an instructor I can see why you feel threatened by my approach but please, don't play the disdain card. It's passe.

And yes, I am trying to save a buck, how did you know. How many kids do you have because I have three and two just came back from the dentist needing braces. How much do braces cost you ask? - Oh, about as much as fundies and some kit. How do I explain blowing that on a whim that I then decided I didn't want to pursue to my wife? I asked them if they couldn't just accept being ugly because I think I want to go deco diving but they said no Selfish gits.

Lack of disposable income is a fact of life for me (and some others I suspect). Some may believe this precludes exposure to basic deco diving but I do not. I substitute intelligence, patience and resourcefulness and, so far, it has worked well. It turns out, those attributes are just the sort of thing an advanced diver might want in their toolbox so I guess I lucked out that way. YMMV.

But again, let's review my heresy:

1. Spend way more time at OW doing basic rec dives developing core skills.
2. Move into deco slowly instead of with both feet (and wallet). Leave doing the Doria for next week. Do 100' first.
3. Get a feel for the planning, discipline and boredom without incurring big risks.
4. Still interested? Take a course and spend some money.