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

[DevonDiver]

Do you think the many deep air / light deco (bounce?) threads are promoting deep air / light deco (bounce?) diving?

Yes.

I think that involvement of many highly experienced, technical and/or dive professional level divers in those debates adds some sanction to those activities.

I think that such debates often champion the 'rights' of divers at the expense of stressing the 'responsibilities' of divers.

I think that 'light deco' is deco. Deco is technical diving. It doesn't belong in the recreational diving area.

I think that it is prudent and ethical to support recommended limitations for recreational divers, when addressing a global, public audience.

Do you think it would be helpful to an adult discussion to have working definitions about what we are discussing; like perhaps a definition of a deep air / light deco (bounce?) dive?

In the right forum area, yes. I've joined in now, only because the debate has been moved to an appropriate area. From the agency definition below, you can see that this 'level' of debate it is firmly reserved for the technical diving sphere.

To contribute to those definitions, here is what PADI say:

PADI TecRec Instructor Manual / Tec40, Section 4:

E. “Bounce” dives

1. A short dive to any depth is called a “bounce” dive.


a. The definition is imprecise – what one person calls a bounce dive another may not.


b. It is possible to make dives within the scope of Tec 40 qualifications that some would be consider bounce dives.

2. There are some anecdotal concerns about bounce decompression dives

a. Some people think DCS data indicate that short, deep dives with short decompression requirements have a higher DCS risk than would be expected based on decompression models.


b. Again, definitions of “short” and “deep” and “risk” are subjective in this context.


c. The concerns are hypothetical and not quantified, but they exist nonetheless.


3. To minimize bounce dive concerns (at all levels):

a. Plan your dive with your computer set for air or an EANx with less oxygen than you actually use.


b. Use a single gas computer, or if using a multigas computer, leave it set for your bottom gas, but decompress with an EANx blend with more oxygen.

 

[VooDooGasMan]

Well Its a start Devon

 

[VooDooGasMan]

I liked moonglo's post but was locked when I read it. Not sure his way of teching but it sounds like what I was pushing for in that it is something that should not be shrugged off with diver progressing fast in the wants for some deep diving.

 

[gmanstan]

From what i can see "Deep Air Bounce Diving" is something like "Street Racing" which I did a lot of when younger, and survived. but more just from pure luck of the draw more so than by following safety standards that professional,better trained people would practice. Its your life, & if its the thrill you seek its your right. just know you are pushing the odds.The reason that the agencies have "Suggested limits" is to better the odds for the masses. Push the envelope at your own risk . As Clint Eastwood said" ask yourself do I feel lucky ..Well do you punk? "

 

[Centrals]

Technical deep air dive, what is wrong with it?
Completed IANTD Deep Air and Adv Nitrox in 98 and Technical EAN a yr later.
In those day the Technical EAN was 60m max and I believe it had been changed to 50 odd m now.
We normally dive to around 54m for 25 mins BT and using 50 and 100 for deco. Total dive time is around 60 mins.
We will add He if we are penetrating wrecks over 50m deep in OW.

 

[DevonDiver]

Technical deep air dive, what is wrong with it?

Nothing IMHO.

The initial disagreements concerned deep air 'bounce' diving within the recreational community.
i.e. non-technically trained divers who might choose to 'bounce' down to depths beyond 40m, using air and/or a single cylinder.

To me, anyone who has developed advanced skills and knowledge-base through technical dive training is in a position to make an informed and responsible personal decision about their dive plan; which includes gas choice/s and relevant depths thereof.

However, without that training and knowledge, a diver may make extremely imprudent decision, based upon a lack of knowledge of, or respect for, risks that they fail to comprehend.

 

[DuboisP]

that's a definition.
i have another one.
in France, we're trained to do deco diving and dive air until 60 m, depending on your level of training and legal regulation.
this legal regulation applies when you dive with your club, a commercial charter, but not if you're diving by your own.
so, by diving 40 m by 20 min, you do deco diving, and it's not technical diving in our definition.
in our system, my opinion is technical diving begins by bringing and using a 2nd tank of nitrox or oxygen to do your deco.

some people dive or dived air after 60 m, but they're uncommon.
i dived air until 52 m and never have the opportunity to go deeper with air, and it will depend on conditions
cold, no visibility, no slope to follow ? no, thanks
hot, visibility, slope/anchorage to follow ? maybe

now, past 50 m, i like to have a tank of oxygen to do deco, and i prefer to dive light trimix.
i encourage people to do the same.

 

[Hydreliox]

Do you think the many deep air / light deco (bounce?) threads are promoting deep air / light deco (bounce?) diving?

No, due to the number of people who come on and instantly slate anyone who suggests the idea. If anything these threads actively discourage people to do deep air dives.

Those who have a genuine active interest in deep air should, in theory, be using the threads to gather information and experiences from other divers so they can plan their dives with the most information available to them.

Whether or not the general SB user looks at these threads and thinks, "hey, yeah that sounds cool, I'm going to try that" is in a way irrelevant. If people don't wish to do the research or training through any aspect of their diving is upon their head.

As for 'light deco' (read: deco), I believe it is something BSAC teach from a basic level in a recreational environment, and there are other agencies who teach deeper air anyway (PSAI?). Not all agencies necessarily agree to air after 40m being dangerous and not all agencies agree that decompression dives are technical dives.

Personally the 'average' recreational diver should perhaps be prepared with more PP02 knowledge, more in depth information in to N2 narcosis and understand more about 02 exposure/CNS/OTUs.

Do you think it would be helpful to an adult discussion to have working definitions about what we are discussing; like perhaps a definition of a deep air / light deco (bounce?) dive?

Yes these discussion should be happening openly to either prevent, assist or provide further knowledge to those who wish to look at deep air dives.

However, I am a firm believer there are people out there discussing these things (internet divers) or people out there getting on with it - and that applies to all aspects of recreational and technical diving.

Just my 2 worthless pence.

 

[MauiScubaSteve]

....

Those who have a genuine active interest in deep air should, in theory, be using the threads to gather information and experiences from other divers so they can plan their dives with the most information available to them.

....

In theory, that is nice, but I think the divers most in need of the information are not "researchers" of that caliber. I try to help by posting old quotes from real experts ...

You know some of the most meticulous work I know of being done underwater is archaeological documentation and recovery. Now Texas A&M does this every summer with an excellent safety record on ancient wrecks down to 200 feet and beyond on air. They just can not get or afford to use mixed gasses. They are now using some O2 for deco, on some sites, sometimes

Now the quality of the divers is nothing to be admired being, at most, AOW, and many with less then 50-100 dives total. Now I wonder how they get that work done on air without a deep cert, mix cert, deco cert, wipe my ass cert, .........?

Bodrum, Turkey - Institute of Nautical Archaeology

I will admit that these dives are more controled then many we do, but Perhaps, just perhaps there is not as much to this stuff as some would make you think.

.... I see and perform bounce/no-D dives on air much deeper than 130' all the time on a single. It was not uncommon in my circle from early 1960s through today. Of course we knew how to read a table and understood diving physics and physiology by graduation. We also knew enough to slowly work our way deeper and manage challenging conditions. For some reason, modern diver training demands a new merit badge for learning to tie a new pair of shoes.

This is the Advanced Scuba Discussions forum and this subject qualifies. Given that deep bounce dives have not been unusual or especially noteworthy since the 1950s, it is unfounded to say they can’t be done safely. There is some risk and a minimum level of education and experience required just like all other forms of advanced diving.

Some members may even need board usage hints; like the fact that clicking on the little blue box with double arrowheads in the quote takes you to the thread where that quote is from.

 

[DevonDiver]

in France, we're trained to do deco diving and dive air until 60 m, depending on your level of training and legal regulation.

As for 'light deco' (read: deco), I believe it is something BSAC teach from a basic level in a recreational environment, and there are other agencies who teach deeper air anyway (PSAI?). Not all agencies necessarily agree to air after 40m being dangerous and not all agencies agree that decompression dives are technical dives.

This is, indeed, the case with BSAC and other CMAS evolved European organisations. However, the deco is extremely light and governed by tables.

To be honest, I think it's an anachronism - something that exists purely because the relevant procedures haven't been updated, in line with modern technology, training opportunities...and, well, community consensus.

BSAC has, only in recent years, begun to embrace 'technical diving'. As their 'technical board' continually establish their ground, it'll be interesting to see what developments occur at the Advanced Diver/First-Class Diver levels with regards to permitted decompression. I'd image that, as of now, the majority of clubs would preserve decompression diving activities for those who had completed the relevant technical training.

What's more, many of those BSAC divers doing 'light deco' according to the BSAC '88 tables will be properly equipped, experienced and well-versed in the necessary procedures. Diving in doubles (aka 'twinsets' in the UK) is quite commonplace, given the preponderance of deep, square-profile, wreck diving that is pursued there.

From my experience, a First-Class BSAC diver, in doubles, is more than a match for a newly certed AN/DP diver from another agency. There's simply no question that these are 'recreational' divers, bounce diving into deco with a single cylinder and unproven dive skills.

As for France... well, it's just France. French people live there. Adhering or recognising any form of international consensus seems to be an anathema to their national culture

Whether or not the general SB user looks at these threads and thinks, "hey, yeah that sounds cool, I'm going to try that" is in a way irrelevant.

To you maybe, but not to others.

Posting on a public internet forum, on the basis of establish credentials and experience, brings a form of responsibility. Whether you wish to recognise it or not, such discussions can easily be viewed as advocating an activity. Advocating something from a position of authority is a form of encouragement... a 'green light'.

Personally, I wouldn't want to live with myself, should my 'right' to discuss a contentious subject on an open public forum lead to someone else taking my 'advice' and killing themselves.

When I do share such information with a less experienced diver, it is in a personal/real-life context; where I can balance the discussion against my understanding of that person's character and mindset... and also balance a theoretical debate with the reality of the risks taken and the consequences of those risks.

Debates here on SB rarely have that balance...and never have that understanding of the readers' mindset or intentions.