Pelizzari 75m "record" dive - air in suit or extreme farting?

[pim]

Looks highly suspicious.

It is quite common to redo part of these dives for promotion purposes.....the official images are often not good enough for the TV/Film guys/girls so turning points, ascends, etc are often redone only to be able to edit a good clip. I, as judge, have witnessed these retakes several times and I find this very good format as these images sell the performances and our sport a lot better than the boring uncut videos from several official cameras.

note; As I have, as result of my function as AIDA Sport Officer, loads of official video material from AIDA World Records and have seen many of those I can tell you many clips seen here or for example on Youtube differ from the official AIDA-tapes as used by the judges. If this is the case with this record I can not tell as those tapes are in Italy at the moment.



Grtzzzzz Pim

 

[fcallagy]

Either you have never seen anyone come back from a deep dive, or you don't have a very good monitor. Even if it did look like the air was coming out of his nose (which it clearly doesn't, look at 2:15 - 2:18) that would be an absolutely massive amount of air to be breathing. You certainly *can* breathe air back in from your sinuses, and even if he didn't, at the depth he must still be then (you can see divers above, and the surface further up, so, say, 15-20m) it looks like more than a lungful to me. I can't imagine he would empty his lungs after a 75m dive at 15m. Looks highly suspicious.

Jeremy welcome to db but just to be aware Eric has seen plenty of people coming from deep dives and has done plenty of very deep dives himself, trust me je knows what he is talking about. I don't think anyone is really accusing umberto of cheating in this vid and the fact that its such good quality means it was proabably done for promo.

 

[jeremyanywhere]

Hi Feargus, thanks for the welcome. 2.5 years late, but kind all the same. I believe I said "or you have a bad monitor". The original poster of the video has obviously studied it, and is interested in starting a discussion about the air. To just categorically state "he is exhaling out of his nose" without close study of the video I think is unreasonable. I am also not accusing Pelizzari of cheating, but the video sells itself as official footage, really, and I don't think it is. I think Pim's response is the most balanced and valid. Perhaps he was doing something else to re-enact the dive for the photographers... (we have just been doing that today)...

 

[trux]

I do not know, Jeremy, if you have looked at the video, but I did. And if you look at it closely enough, you clearly see that Umberto swims through several huge clouds of bubbles from scuba divers. And that's the very case also at 2:00 onwards as stated in the initial post. You can clearly see that the bubbles are even above him, despite that he ascents faster than the bubbles, so these bubbles definitely cannot come from his suit. They are simply trapped into the bow around his head as he swims through the cloud.

That told, it does not exclude that they also staged a clip for the media adding some more air into the suit, but I do not think it is necessary to explain what we see in this very video.

 

[jeremyanywhere]

Hi Trux,
Firstly, I think you are right, studying this particular clip in detail should not be considered as a question of the authenticity of the dive.

However, I have studied it in great detail. It is slightly better quality in the non-embedded YouTube, HTT etc. youtube.com/watch?v=fhyj2VZGcFw

My detailed analysis is this:

From 2:05 air is clearly coming out from under his hood. The Cressi logo on his forhead is still clear, so it isn't a bubble that he has swum into, or that has come from above.
At 2:09 you can see an air bubble coming from his nostril. It isn't big. From 2:10 some of the air might be scuba bubbles that he is swimming into, these are tiny, though, (from fairly deep divers). Only from 2:12 onwards do the scuba bubbles look large enough to stick or create any of the "head bubble" effect, but by 2:17 he is past the bubbles and at 2:21 and 2:22 there is a sudden surge of air / bubble size that I just cannot believe is a head bubble. The question is, what was he doing during this particular piece of footage? Did he have air in his suit?

 

[vali]

why just not ask him????

 

[trux]

I don't agree with your analysis, Jeremy. First of all air bubles from deep scuba divers are not tiny, but quite oppositely they create huge clouds of air because of the expansion during the ascent. The individual bubbles may be tiny, and hence not well visible, but as soon as they enter the bow, they merge, and create bigger ones. The bubbles are trapped well in the bow, and as you can see, due to the ascent speed, they do not escape upwards, but downwards, and it takes a rather long time before they quit the bow. Just at 2'00" - 2'02" Umberto swims through one of the huge clouds, so quite clearly the air you can see at his hood at 2'02" and later comes from that cloud and nowhere else.

Use the stop button and you will clearly see bubles above the Cressi logo on the hood (i.e. at 2'05"), which clearly cannot come from under the hood, but are bubbles trapped as he swims through them, and merged together. Don't forget that the bubbles also expand as he ascends, so grow in size, and that's especially well noticeable near the surface, when the expansion gradient is the biggest.

So far I see no mystery there, and although I do not exclude some air in the wetsuit, it certainly is not necessary for explaining the effect we see.

 

[azapa]

all i can say is that Umberto never advocates pre-surface exhales, even post surface exhales are very controlled, the emphasis is on a full inhale. On the other hand Martin S. (and of course the PFI crew) DO advocate pre-surface exhale in last few meters. A big gap in thinking, but both has its virtues.

About the bubbles? no idea. A bit from sinuses, rest from scubies, and maybe the "look cool factor too" Don't forget how much Umberto likes NLTS sled and the inherently bubbly rides up, maybe on film they wanted some of that look?

 

[jeremyanywhere]

time before they quit the bow. Just at 2'00" - 2'02" Umberto swims through one of the huge clouds, so quite clearly the air you can see at his hood at 2'02" and later comes from that cloud and nowhere else..

Trux, I don't see this at all. I have had a close look, and at 2:00 to 2:04, the water is distinctly blue and clear of scuba bubbles. I have the misfortune of diving above deep tech divers every day, and I have never seen their bubbles reconnect on any divers' heads. I can always tell how deep the divers are by the size of the bubbles. Shallow divers send up those lovely mushroom shaped bubbles that you can see your face in, and the deep tech divers' bubbles are tiny by the time they reach the surface. Yes, sure they expand, but they break up and almost turn into a mist.

Anyway, ThomasB has posted a response in which he says that he has heard of Umberto Pelizzari putting air in his suit for the effect it gives in photo shoots. Most likely that is what this is, after the actual record attempt this was a staged ascent for filmography purposes. Looks lovely, if a wee bit odd... The legend is untainted.

 

[efattah]

For the record, I often exhale almost all the air in my lungs at 20m on the ascent. Sometimes I forget because I'm too narked. But if I'm clear headed I do it, and it helps a lot. It does create a huge cloud of bubbles that continues to surround me long after I surface.

 

[Aber]

In what way does it help to exhale that much air this deep? Don't you loose your positive buoyancy this way and must make more effort to ascend? What's the rationale behind this action?

 

[azapa]

a big advantage on paper is that exhaling allows (demands) an immediate inhale on the surface. you will also see top athletes doing the last 10M or so real slow anyway to reduce nitrogen buildup.

In real world situations, maybe with less than perfect safety, the disadvantages are obvious: with the exhale you exaggerate the all ready steep gradient of the PO2 reduction (sometimes called "vacuum effect"), making a BO more likely, and to make matters worse, you will be less buoyant and more prone to sink.

 

[Aber]

Exhale at 10m or so sounds ok, but at 20 as Eric Fattah suggests?

 

[Mullins]

Reduce nitrogen buildup by exhaling near the surface? Never heard of that, and I don't see how it would have an effect. Wouldn't you be off-gassing into your lungs by that stage anyway, having taken on nitrogen during the deeper part of the dive?

Eric, do you do it to reduce BP change caused by expanding lungs?

 

[trux]

the disadvantages are obvious: with the exhale you exaggerate the all ready steep gradient of the PO2 reduction (sometimes called "vacuum effect"), making a BO more likely, ...

This is actually not completely true. The partial pressures of the gases remain to great extent uninfluenced by the exhale. There is no reason for them to change when you exhale.

The partial alveolar pressure of oxygen is determined by two main factors: 1) the absolute pressure of gas in lungs, and 2) the ratio of the part of oxygen to the total volume.

1) The pressure in lungs is only dependent on the ambient water pressure, and is equal to the ambient pressure on inhale as well as on exhale, hence no change here. There may be a very slight overpressure due to extreme packing just on surface, or perhaps still a feet or two under it, but definitely no anywhere deeper. The overpressure may be accentuated by the progressed bloodshift on ascent, but in the same time reduced due to the loss of gas volume due to oxygen consumption (the CO2 production is slightly lower). But still, any excess overpressure concerns only the very last feet or two, hence the impact of exhaling on PaO2 during the ascent is inexisting.

2) By exhaling you do not change the ratio of O2 in lungs (at least not in short term). You cannot exhale oxygen without exhaling also the other gases in lungs, hence the percentage of oxygen after the exhale remains practically identical to the level before it.

So, as you see, there is no way the PaO2 could change, and strengthen so the "vacuum effect" due to exhale, as is often incorrectly claimed in freediving courses, or even in some books.

That told, when remaining longer time with considerably lower volume of gas in lungs, the gradient of oxygen intake from this remaining volume has proportionally stronger effect, so when the exhale is done a long time before surfacing, it could indeeed contribute to quicker drop of PaO2. There is though no such risk when done on the last few meters.

From this point of view the exhale at 20m as Eric tells, is surprising to me too, since it is still rather deep; but I guess he relies on strengthening the Diving Response, and perhaps uses it also for buoyancy control to slow down the last phase of the ascent (reducing so the risk of DCS). He will certainly tell us more.

 

[Mullins]

If I exhaled almost all the air in my lungs at 20m I'd probably come to a complete stop!

 

[blueface]

trux, will exhaling prior to surfacing cause a loss in thoracic pressure and cause oxygenated blood to stop in the carotids and possibly lead to a black out? This is something I always thought was true. What about forcefully exhaling after surfacing? Even if the partial pressure does not change, the availability of Oxygen can. Is this correct?

Thanks!

Skip

 

[trux]

Yes, the drop in blood pressure after the exhale is more important than the gas volume reduction itself, and that indeed leads to pronounced hypoxia, when you exhale on surface. However, during ascent this effect is to some extent limited by the continuously expanding air in lungs, so the drop of blood pressure will not be immediately the same and so sudden as when done upon surfacing.

EDIT: in other words, what I tried to tell is that the alveolar pressure change due to the ascent (the ambient pressure change) is way bigger than the change of intrathoracic pressure due to the exhale alone.

Upon surfacing, and starting to breathe, there are also some additional effects that lead to worsening the hypoxemia even shortly after you start breathing - for example the releasing vasoconstriction, the change of chemistry (shift of the Bohr saturation curve), etc.

 

[blueface]

Thanks trux!

 

[azapa]

Reduce nitrogen buildup by exhaling near the surface? Never heard of that, and I don't see how it would have an effect. Wouldn't you be off-gassing into your lungs by that stage anyway, having taken on nitrogen during the deeper part of the dive?

Eric, do you do it to reduce BP change caused by expanding lungs?

Dave :head:head reduce buildup BY GOING SLOWER or even a short hang is what i was referring too