Is Deep Air / Light Deco (bounce?) Discussible on ScubaBoard?

[MXGratefulDiver]

I disagree a bit with Yoda. There is a try..
Try is what you did when you sat yourself up to fail

The effect of thinking "I WILL do it" rather than "I'll try doing it" is seriously underestimated..

At all levels. Had an OW student in the pool this past week-end who didn't believe she could pass her swim test. I knew she could ... I just had to figure out a way to help her know it. I did ... and so did she. Rather easily, in fact ...

... Bob (Grateful Diver)

 

[MXGratefulDiver]

I think the point was that the cost of failure is huge with deco diving. It is not a simple matter of you rolling backwards and possibly a light bump on the noggin. You do not try deco diving. You either do it right or pay the price.

... as with most things diving ... it depends.

Screwing up deco doesn't guarantee a DCS hit ... too many variables going on in your body to say with certainty what will happen. But it does raise the stakes. Depending on the degree of screwup, it can raise them considerably. Considering the consequences of getting it wrong, it's a risk that should be avoided if it all possible ...

... Bob (Grateful Diver)

 

[DevonDiver]

The problem I see with trainee tech divers (and remember from my own training) is not a lack of self-belief, it's a vast over-confidence and over-estimation of personal skill.

It's the primary reason why I have strong opinions about keeping 'recreational' divers away from deco and depth until they've experienced that wake-up call.

 

[dumpsterDiver]

That was my point exactly.

Buddy breathing while maskless is one thing. Holding a precise depth for a deco stop while doing it, then ascending to the next level, regaining buoyancy, and holding that precise depth while doing it is another. The normal buddy breathing technique goes out the window as you hold perfect trim, touch the knot on the ascent line with the right hand to be sure you at the right depth while you reach back with the left hand to dump air from the rear dump of the wing to adjust buoyancy, hoping you will soon feel a regulator at your lips soon or that you can complete the buoyancy act in time to give the regulator back to your buddy (left handed) is another.

You get to hold onto a line too? Man you certified tech divers do some tough stuff...

 

[ScubaSteve]

... as with most things diving ... it depends.

Screwing up deco doesn't guarantee a DCS hit ... too many variables going on in your body to say with certainty what will happen. But it does raise the stakes. Depending on the degree of screwup, it can raise them considerably. Considering the consequences of getting it wrong, it's a risk that should be avoided if it all possible ...

... Bob (Grateful Diver)

And that is the point.

 

[Tigerman]

The point of tech diving is to raise the stakes for screwups?



Sorry, couldnt help myself..

 

[waterpirate]

Tech training 101. They do thier first deco dive simulated. Dive nitrox with tables for air. Then when the confidance overwhelms the skills and the stops get butchered or blown the only pain that gets inflicted is from the instructor via a slap to the back of the head later on the boat.
Eric

 

[boulderjohn]

You get to hold onto a line too? Man you certified tech divers do some tough stuff...

Glad you asked.

Yes, whenever we do a blue water ascent we shoot a bag and thus have a line for reference. We put knots in it every 10 feet so that we can identify our required stop depths without having to refer to gauges. In this case, I was not hanging onto the line but was instead touching the knot so that I knew my depth, since I could not see it.

This is actually an important point. That ascent line is one of the safety measures we take in anticipation of things screwing up. Having those safety factors and practicing with them is what allows us to have the confidence that we can survive failures at depth. Not having those safety factors or that training is what concerns us about people who don't know what their are doing relying on luck instead.

 

[MauiScubaSteve]

The problem I see with trainee tech divers (and remember from my own training) is not a lack of self-belief, it's a vast over-confidence and over-estimation of personal skill.

It's the primary reason why I have strong opinions about keeping 'recreational' divers away from deco and depth until they've experienced that wake-up call.

Ahhh; you evidently feel that by not talking about deco in "recreational forums", other than to "just say no", then recreational divers will self regulate and always never go into deco. But then two recreational divers with different computers notice what Bob described, and while talking on the boat someone with another, more aggressive computer sees that they did not get bent ...

I can remember my first few OW classes as instructor, and during the equipment demonstration, or later when preparing for a dive, we would reset the max depth needle to zero, and every now and then the needle of those rental depth gauges was "stupid deep". Back then my mind could not properly process that data ...

Going back to Bob's post on the differences between Vytec and Versa; does one have to show a tech cert to buy a Vytec or Versa?

Going back to my Suunto Vyper; my less than 10 min ASC time dives have always shown 10 feet as the ceiling. The floor of the stop, as described in the manual, is not much concern imho, because the manual indicates one "should" stay in the "optimal deco zone" which it defines as "ceiling to 6 feet deeper than ceiling. The manual goes further to say that due to the undulating nature of the ocean, 14 feet is Suunto's minimum recommended depth.

What I get from that is that 12-16 feet deep is a reasonable range.

And then there is this ...

WARNING! DECOMPRESSION DIVES ARE NOT RECOMMENDED!

Decompression diving limits the divers ability to ascend directly to the surface and may substantially increase the risk of decompression sickness.

However, if through carelessness or emergency you are forced to exceed the no-decompression limits on a dive, the dive computer will provide decompression information required for ascent. After this, the instrument will continue to provide subsequent interval and repetitive dive information.

 

[boulderjohn]

Going back to my Suunto Vyper; my less than 10 min ASC time dives have always shown 10 feet as the ceiling.

So is this part of what you are referring to when you speak of a "bounce dive" or "light deco"? Are you saying that light deco means that only one deco stop is required at the normal safety stop depth?

When I did the San Francisco Maru dive I mentioned earlier, I was carrying a Suunto Cobra- the same computer algorithm as the Vyper. It had my first ceiling at something like 45 feet--I don't recall exactly, since it was a number of years ago. Would that be what you consider light deco, or would the requirement for several deeper stops not fit your definition?

I am still waiting for the bounce dive advocates to define their terms--perhaps this is a start.