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Freediving FAQ

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.

Should there be a freediving FAQ?

  • Yes

    Votes: 23 100.0%
  • No

    Votes: 0 0.0%

  • Total voters
Ummmm, sounds like a good subject for diffences of opinion.

OK, I'll stick my neck out and say I think it is a good idea if handled correctly. A gentle approach to its presentation is probably needed to avoid insulting some people. IMHO it ought to be quite brief, answer the basic questions and then reference a few of the better threads on each subject (now we can really disagree on which ones are best, a tough call for anybody). If someone isn't very serious, the FAQ will be sufficient. If seriously interested, the real info is in the threads and this approach would teach how to use them in gathering information and understanding the diversity of opinion, a necessary skill to get the most out of this forum.

This approach would be more time intensive to implement than a simple FAQ, because it would require someone to review and probably update the list of threads every so often. That's both good and bad, I guess.

Object-Oriented programming has scarred my brain tissue causing me to visualize a multi connected collection of documents with every keyword being a hyperlink.
I tend to overcomplicate things.
If DB is a community, and communities generate a multiplicity of opinions on any subject then a FAQ could be as simple as an explanation on how to search DB's forums.
I started to explain my vision in my initial post, but the truth of it is that that vision is relective of the manner in which I learn, and might not be relevant to the general populous of new and curious.
With regards to personal needs, I am still, despite countless hours of reading, clueless about:
1) The relationship between internal action of lungs and the physical sensations involved with dives involving compression beyond reserve volume. (how to tell if I am killing myself)
2) Proper finless kicking technique.
3) Hands-free equalizing
4) Mysterious unspecified non-frenzel techniques for equalizing at depth.

There are people that understand these things well enough to explain how they do them, and how a person with certain prerequisite skills could aquire that skill.

If such documents were put together covering from the most basic to the most complex skills, then a beginner free diver could cut through the opinions and learn enough to develop their own opinions.

If such documents were linked together in a single interface, it would be very easy to self-educate.

Differences of opinion should not, in my opinion, be applicable to such technical descriptions.
Originally posted by JasonWelbourne
With regards to personal needs, I am still, despite countless hours of reading, clueless about:
1) The relationship between internal action of lungs and the physical sensations involved with dives involving compression beyond reserve volume. (how to tell if I am killing myself)
2) Proper finless kicking technique.
3) Hands-free equalizing
4) Mysterious unspecified non-frenzel techniques for equalizing at depth.

1 - If you're not nudging 200m then someone has been at that depth before and survived :)
2 - Watch stigs dynamic video
3 - Imagine there's a golf ball :))) sitting on the back of your throat and try to stretch the back of your throat over it
4 - Pick up a book on diving medicine or physiology
I took the liberty of collecting some questions. Some are frequently asked, others just plain useful and some are frequenlty thought of but too embarassing to ask ;)

I'll leave the answering to others, but here's my idea: pick as question and formulate a good answer. The kind you would publish, and reply to this thread. I'll keep updating this post with the answers and perhaps when it's "done", Stephan or someone can pick it up and put it in the front page or something. Aswers should be short and only contain the essential. Let's keep this a "beginners FAQ", no need to go into empty lung diving or anything. If need be, we'll make an "advanced FAQ" later?

Links to articles, sites and db threads related to each question would be helpful also! And feel free to suggest new questions or removals of questions that you feel are not for this context.

Edit: This forum doesn't support such huge posts, so I temporarily moved it to:
Deeperblue FAQ
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  • Like
Reactions: loopy
That just about covers everything!

There's a good freediving glossary somewhere - I'll try to find it and post the link.
Well I'm by no means an expert, but I'll give a couple of these a shot - feel free anyone to add anything, change anything or just plain make fun of me :)

4. Q:What are co2/o2 tables?
A: A table is set sequence of apnea events, lasting for a certain duration with a certain rest time in between. For example, a basic table may consist of five breath holds lasting 2 minutes, with a rest time in between each hold of three minutes.
CO2 tables are designed to build up the levels of CO2 in your body (called "hypercapnia"). CO2 levels are your primary trigger for the urge to breathe, and also determine when you start getting contractions. A typical CO2 table has a constant hold time (usually half your maximum static, say two minutes) with a decreasing rest time (say, starting with 2 minutes rest, then halving the rest in between each static). This table may then be carried out as:

Breathe up
Hold 2:00
Rest/Breathe Up 2:00
Hold 2:00
Rest/Breathe Up 1:00
Hold 2:00
Rest/Breathe Up 0:30
Hold 2:00
Rest/Breathe Up 0:15
Hold 2:00

This would be called a "two minute CO2 table". There are also other variations on the table (ie hold until a certain number of contractions, take one breath, then hold until the same number, take one breath, etc).
An O2 table is designed to lower the levels of oxygen in your body, that is, to get you hypoxic. In contrast to a CO2 table, the rest periods are ususally constant (say two minutes) where the hold time increases (say starting at two minutes, and then adding a minute each time). For example:

Breathe Up
Hold 2:00
Rest/Breathe Up 2:00
Hold 3:00
Rest/Breathe Up 2:00
Hold 4:00
Rest/Breathe Up 2:00
Hold 5:00

is an example of an O2 table. Variations on O2 tables include "negative tables", which consist of an O2 table done after a full exhale (ie on "empty lungs").

11. Q:What is equalizing? What are Frenzel technique, BTV, Valsalva? How often should I equalize?
A: As a diver descends, the pressure changes experienced cause the ends of the Eustacian tubes (contained in the inner ear) to seal up. If further pressure changes are experienced, this cause cause severe pain and a rupturing of the ear drum. To compensate for this, the pressure in the Eustacian tubes must be equalised - conciously on the descent, and generally automatically on the ascent.
Basic equalisation (known as the "Valsalva" method, after its invetor) is carried out by pinching the nose, then trying to forcibly exhale through the nose. A "popping" feeling should be felt in the ears if this occurs properly.
Many people (especially beginners) find equalisation a hurdle to cross when they first start freediving. This is due to individual differences in physiology. Because of this, there are multiple known techniques for equalising the ears. BTV or "hands free equalisation" is exactly that - a way to equalise without pinching the nose. Frenzel equalisation is another method (involving placement of the tongue) which is generally considered more effective than Valsalva.
Equalisation should occur before any pain is felt. This means (generally) every few meters in shallow depth, then less as the pressure changes are more acute at depth.
When significant depths are reached, the volume of air in the lungs is compressed to the size that they would be on land if all the air was forcibly exhaled from them. In this instance, it is not possible to get the required pressure into the mouth to equalise. Because of this, another technique known as the "mouth fill" technique was devised. At a shallower depth than where residual volume is reached, the mouth is filled up with air from the lungs. The diver then closes off the soft palate (located in the back of the throat) to hold this air in the mouth (which is at a higer pressure than in the lungs). Using a mouthfill like this at an appropriate depth has enabled many divers to still equalise to extreme depths.
  • Like
Reactions: jome
Thanks for the input loopy, good stuff.

The forum doesn't support messages longer that 10000 characters, so I had to move the post to my own server for now. But once it's done, if it's good enough, I'm sure it'll find a home here somehow.

Please keep them coming, this is a team effort :)
Good Thread folks - once it is in a decent form we'll look at integrating it into the site.
Q:What are reasonable exepctations for a newbie?
A: Concrete reasonable expectations are dangerous for newbies. The proper course of action for establishing personal expectations is personal performance. Do dry statics. Learn your limits there, where it is relatively danger-free.

I am not sure how to do it, but I think perhaps we should create a poll to gather the follwoing types of info, and publish the poll results as the answer to this question with the warning above.

Personal newbie progress
Aug 2004 (The begining) - Nov 2004 (Now)
Dry static repeatable no breathup - 1:30 - 3:00
Dry static PB - 3:00 - (4:00 as of Sep) ?
Constant w/o fins - 5m - 20m
Free Imersion - 15m - 25m
Variable weight - ? - 30m

Q:What is packing?
A: Packing is inflation of the lungs beyond the capacity acheivable through ordinary inhaling. This can be safe, but it can also be very dangerous. (Can someone explain the dangers of packing, mechanisms to prevent dangerous over-inflation etc.?)

How to:
This is in the Frenzel-Fattah FAQ
[I assume that this is ok to quote but if it is not someone please edit my post. I do not wish to infringe on what is eric's.]
1. Close your mouth
2. Exhale against your closed mouth, filling up your cheeks
3. Squeeze your cheeks and push the air back into your lungs
4. Repeat 1-3 again and again until you can fill your cheeks, and push the air back into your lungs easily
5. Find a drinking straw
6. Put the straw in your mouth
7. Suck air through the straw
8. Inhale through the straw
9. Notice the difference between inhaling through the straw, and sucking through the straw
10. Inhale to your maximum through the straw
11. Suck air through the straw, into your mouth
12. Take the straw out
13. Use your cheeks to push that air back into your lungs
14. Suck air into your mouth without using the straw
15. Use your cheeks to push that air back into your lungs (do not swallow the air into your stomach)
16. One suck/push cycle is called one ‘pack’
17. Start over, with no straw
18. Inhale to your maximum
19. Pack your lungs, again and again, until you can’t fit anymore air in your lungs, or until you feel discomfort. Count how many packs you can get. If you have access to a spirometer, you can measure how much extra air you are actually getting. Most people get between 0.8L and 4.0L of extra air.
Interesting the difference in response that time seems to have allowed!!?? June 2002


It once again think it is a wonderful idea and essential. I just thought there is already the forum structure in place here at deeperblue, which supports an organized means of presenting topics and subtopics as opposed to a standard flat FAQ .
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Forums make for a lot of information to sort through.

In my case FAQ didn't acurately describe my vision.

I don't beleive that there are many questions for which a concrete answer can be formulated in freediving, but I do think that some very concrete how-to's should be put together in a cross-linked fashion for all technical skills which can be accomplished in a repeatable programatic way, and which can be taught to a person with specific prerequisite skills through an electronic medium. Such things are not so much subject to differences of opinion. It's not material for a forum. It is material for a resource.

The only such documents I have seen are the Frenzel-Fattah Howto, some fin technique descriptions on the GUE website, and appantly there is a document of BTV that has never been properly translated to english. But there are so many more skills to be learned. There are so many more phenomenon which lack a good technical description.

If all of this material were seperated into seperate HTML files, organized in a comon structure, and crosslinked keyword style, it would make one resource that would be VERY easy for anyone to soak up real indisputable information which they could use to develop the necessary skills so as not to be injured.

Other things, subject to severe variance of opinion should probably be worked out in the forums, and in the case of VITAL newbie data, such as proper newbie expectations, should probably be organized into a FAQ, containing, if appropriate, statistical data from forum polls.

I don't know. It's just an idea. I'm not doing much to bring it into existance. Maybe this thread will merely subside into history. Maybe something will come of it which doesn't represent my personal vision. If so, it probably won't be any less helpful. I just got worked up by the Okane thread. I'll forget about it tommorrow or the next day.


I think you mistook the meaning of my post. But I agree with what you are saying and that is what the meaning of my thread was. I only referenced forums in terms of the structure of multiple levels of categorization. But not with the idea that they could be added to by anybody without prior consideration of a moderator. Basically a sensored forum. The whole point was to avoid any costly or time consuming development on something else. Same wave length?
Hi Jason, I've a different oppinion on the "Q:What are reasonable exepctations for a newbie? "

I think allong certain times, distances and depths there should be a little educational warning with it too.
Stifeing passionally for these goals will create unnessesairy samba's and BO's. People's will can override the sensors. Furtermore training to hard (maxing al the time.. etc.) will create serious (mental) blockades, that take a long time overcomming IF the freediver hasn't cast the sport away already.

I think it's important that the newbe should be patient about the numbers and eager to learn the techniques.

Love, peace and water!


My version of an educational warning was the following

Q:What are reasonable exepctations for a newbie?
A: Concrete reasonable expectations are dangerous for newbies. The proper course of action for establishing personal expectations is personal performance.

My language may be confusing, so I will say this again in other words.
A: A newbie should not base their personal expectations on other freediver's performances. All concrete numbers should be avoided as goals because freediving is dangerous. Instead newbies should establish reasonable goals based on their own performance. Even reasonable golas should only be pursued in a safe enviroment.

This can be done by quantifying ability in a safe environment, for instance in a class, or with a dive buddy who is trained and prepared to rescue if necessary, or by doing dry statics if you do not have access to the other things.

Even once you have established your ability, you can NOT multiply it by 125% and set this as a concrete goal. Everybodies metabolism is different. If you are stuck at X, there are exactly two possibilities. Either you are immidiately capable of more, and you are suffering from a mental block, OR you are pushing the limits and X + 1 will involve black out / your unfortunate death. Goal setting is something that should ONLY be done in a safe environment.

[Some people will not settle for this. Some people need numbers. Let's gather some data, and put together some numbers. If no one kept dive logs from day one, let's sucker the new generation of free divers into doing it for us and use their data.]

Can they do that? It sounds like a good idea, but it is potentially moderator intensive. What about democracy? A forum with a main document thread that is always displayed, and each additional thread is a poll deciding if the thread's primary post will be added to the main document. That could be almost automated.
I really like the idea of "self sensoring, hyperlinked freediving bible (or FAQ)", but the fact is, it would be alot of work that no one seems to be willing to undertake. This simple FAQ should be withing our grasp with just a couple of good posts and would be helpful to a lot of newbies.

But a site along the lines of everything2.com or wikipedia would be cool. I've always silently disagreed with the way "karma" is used in this forum. It should not be something that is just sort of given to buddies and nice people. It should be something that is given to someone, who really contributes, something new and useful and as a consequence those people get more rights (such as moderating posts by others, or voting them up or down etc).
If you have time, check out everything2.com. It's and awesome site an has implemented this idea beautifully.

In essence, anyone can contribute an article. Other's can complement it and give them feedback. If the article is inappropriate or sucks, it will be removed. If it's just not very good, it will have a bad rating. If it's really good, it will have a good rating and be elevated to the front page as "cream of the cool". An article that is rated good will automatically increase the person's "karma". At the end of articles is an automatically maintained list of keywords from the article, as links to other similar articles etc. Basically everything is interlinked to everything similar and everything is the topic of everything2. Therefore the name ;)

Something like that, but in smaller scale, would rock.

Oh, yes, there is the freediving manual. Too bad no one's really contributing :/
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That is exactly what I was thinking about. I know how to write back end code for such a system, although I am sure there are already pre-built packages out there. I don't know if DB would even consider expanding their server to support such an extension, but I think that ultimately, if such a resource existed, it would be a super-useful suplement to the kind of information that can be attained from the forums. In the meantime, a FAQ is still a good extension to what we have, and if the freediving manual project is to get anywhere, perhaps upon completion fo the FAQ, it contents should be submited to that resource.
If it is self-sensored, then no need to write anything, as Jome pointed out, and was posted in other threads, the wiki already exists at the link Jome posted. Just start a FAQ section and off you go... Instead of FAQ you might want to call the section "the bare necessities", "the quickstart to freediving", "the essentials", or something along that line, so it is apparent where to look.

I am sure if it starts materializing DB would easily incorporate it, host it, or just link to it.

However, if you insist to create something new, then check out the already created source, in any development language you could possibly want, for wikis at: http://c2.com/cgi/wiki?WikiEngines
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