Compressed air mid-freedive

[minnesota01r6]

http://www.divedestinations.net/content/Feature.aspx?did=2005-7&fid=31

Why not give the freediver your alternate air supply? The only scenario for this solution would be a (rare) entanglement with the descent line or similar, where immediate ascent to the surface was impossible. Breathing from a regulator converts a freediver to a scuba diver, so ascent rates and decompression/safety stop requirements become mandatory for both diver and freediver.

From the research I have done, it seems that it is less of a risk to shoot the freediver to the surface on something like a lift bag (FHOF) than keep them down with you to do your deco stops. If something has gone wrong in the dive, they are better off getting shot to the surface immediately so that they have no deco obligation, and they can be given CPR asap. Nothing would indicate that they cannot switch to scuba when at depth.

so, to answer your questions Thalassamania: (remember, this is comming from a scuba diver who did 1/2 hour of research on the net, take it for what it is worth)

1) nothing, as long as they are conscious

2) deco obligations, 1 breath of mix probably won't be enough to get them to the surface since they have already used a ton of the O2 in their system - it's better to either stay with the safety diver or get shot up on that FHOF thing.

3) as well as the stuff I mentioned, they can activate the FHOF, judge to make sure the diver has reached the target depth on a good dive, and help with malfunctioning equipment

4)

a) Safety divers must act as depth markers, judges and safety for competitors
b) If an athlete should require the assistance of a safety scuba diver, the athlete is now a scuba
diver and under the control of the safety scuba diver
c) At no time, should an athlete breath off compressed gas, will they be allowed to ascend
independently and without continuous breathing off the scuba unit
d) Appropriate safety stops will be followed and the athlete may be passed to shallower safety
scuba divers if appropriate

http://mad06.h2oteam.com/sub/docs/safetyv1.1-eng.pdf

 

[D_O_H]

I think you guys need to let this one go. He is obviously shooting from the hip on a lot of this stuff. This would probably be a lot more productive conversation with someone like Dr. Deco, who presumably will not try to hide a lack of knowledge by radiating unfounded smugness and condescension.

 

[5ata]

Audrey's attempt was not sanctioned by AIDA - it was an IAFD record attempt. As such, they were not adhering to AIDA world record attempt regulations.

 

[minnesota01r6]

my post was merely to illustrate that it is possible to switch from freediving to scuba at the bottom of your dive (something very much debated in this thread)

 

[Thalassamania]

While I greatly appceciate your half hour I was looking for an answer from 5ata, someone who's been there.

 

[5ata]

Thalassamania said:

1) what is there, on an anatomical/physiological level, other than narcosis which we understand, to prevent a freediver at great depth from taking a breath of trimix?
2) if it is possible to take such a breath what, again on an anatomical/physiological level, prevents a free diver from making an exhaling ascent to the surface?
3) Of what use is a safety diver if he or she is not equipped for and can not provide emergency assistance?
4) What references can you supply to support your answers to these questions?

1) This was confirmed by freediver in response #62

2) To my knowledge - due to the extreme pressures at that depth, taking a breath is not possible due to said response in #1

3) There are now new bail out devices that were developed as a direct result of Audrey's accident - you can read my detailed article where I interviewed many top level athletes and trainers on this subject here - http://www.deeperblue.net/article.php/297/ 0/0

4) I have no need to defend my position

 

[minnesota01r6]

5ata - I think there is some comfusion about what is being discussed. If a diver blacks out, then I concede that no air can be given at depth, and the best thing to do is get them to the surface as quickly as possible.

If, on the other hand, an entanglement or lift bag malfunction occurs, and the diver is conscious, they could accept gas from a safety diver and then incur the deco obligations, correct? Or are you saying that once you commit to a freedive you cannot take a breath until you resurface no matter what?

 

[5ata]

minnesota01r6 - you do raise an interesting point.

I think the issue at hand here is specific - ie; a no limits freediver who is at a depth that is too great to even try and inhale off a compressed gas source. Now this subject may be getting beaten to death.

In general, if a freediver, say one doing a constant ballast dive to 106 meters (the current world record), at that depth, the pressure exerted on the divers body isn't great enough to prevent them from taking a regulator if needed.

All of the training I have had up to this point has been about safety - ie; the vast majority of freedivers are recreational - they aren't diving to these extreme depths. Typical depths are in the 10-30 meter range for most freedivers. What I have been taught by the freedive instructors I have worked with - you don't breathe off a tank if you want to keep freediving that day - if you do, you're done and out of the water.

So technically, one can breathe off a compressed gas source, but having done that, the standards by which I have been taught stipulate that you are no longer a freediver, but a scuba diver and are to adhere to scuba protocols for ascent, and surface intervals. And it has been shown that when doing scuba first, there is to be no freediving for 24 hours. That is the safety protocols I have been taught and I prefer to side towards safety.

I hope I was able to answer your question.

 

[minnesota01r6]

That is exactly what I was looking for. Thanks!

 

[5ata]

That is exactly what I was looking for. Thanks!