Technical Freediving: Are Breathhold Divers Ready To Mix It Up? - DeeperBlue.com

[CuzzA]

Technical Freediving: Are Breathhold Divers Ready To Mix It Up? – DeeperBlue.com

Don't let the title fool you, this is scuba related and is worthy of a conversation. Aside from the obvious flaws in the article like this...

In addition to pre-breathing, freedivers might also take their final breath-hold from a scuba regulator underwater, enabling them to take in more gas than they could at the surface effectively accomplishing “lung packing.” For example, taking a breath at 20 ft/6 m (1.6 ATA) increases the breath-hold volume by a factor of 1.6, potentially giving them more bottom time (Krack argues that taking a single breath underwater is clearly different from sustained underwater breathing). Of course, the diver would need to exhale at an appropriate depth upon ascent to avoid an overexpansion injury. Of course, freedivers generally exhale before surfacing, so to be able to immediately breathe.
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The author makes it sound so simple. Meh, take a breath from a scuba tank at 20 ft. Drop down, shoot a fish or try and break your personal best breath hold and come on up. No big deal, you usually exhale just before surfacing anyway.

Anyway, there's a number of other issues here and there's a reason breath holding and scuba don't mix. I look forward to the following conversation.

 

[chris kippax]

I read this last night, I took it as if it was aimed at accomplished freediver's that had completed courses up to that level (instructor). Definitely not for the amateur. I would be keen to give it a go, especially the breathe up on Nitrox, not so sure about the 20ft breath though but after taking his course I may feel different.
From reading the author's bio he is a very experienced freediver so for him it is probably very simple. I have read a story of two free divers that breathed from an sea cave/air pocket at a depth of around 50ft. Upon ascent air poured out from their lungs as they expanded on their ascent. They put it down to there relaxed state that the air was allowed to freely escape from their lungs without injury, but that was just a story with no factual science to back it up.

 

[Esprise Me]

Aside from the danger, I don't get the point. I thought people liked freediving because it was free of the cumbersome equipment and thinky rules of scuba. This seems like the worst of both worlds.

 

[chris kippax]

People dive for depth records and hunting as well. Different stroked for different folks.

 

[CuzzA]

I get the pre and post breathing, but the at depth breathing to increase range and time creates a lot of issues, for obvious reasons.

I found the article posted on a spearfishing group. To me it just seems like a really poor idea to spread the idea. I could see some inexperienced guys giving it a try and killing themselves.

 

[chris kippax]

Darwin doesn't sleep. In the age of information people can get just enough info to be dangerous on almost any topic.

 

[CuzzA]

Darwin doesn't sleep. In the age of information people can get just enough info to be dangerous on almost any topic.

Indeed, but usually bad ideas are not spread through people and outlets viewed as the authority on the topic.

 

[chris kippax]

In years to come you may now appear to be like a Nitrox naysayer from 1970????
Who knows, I am not a world authority on freediving so I am not qualified to make that call. It sounds like Krack has invested a lot more time & energy than you or I in this.

 

[CuzzA]

In years to come you may now appear to be like a Nitrox naysayer from 1970????
Who knows, I am not a world authority on freediving so I am not qualified to make that call. It sounds like Krack has invested a lot more time & energy than you or I in this.

Being ignorant is a bit different than changing the laws of physics. Pulmonary barotrauma and DCS odds do not go down with rapid accents from breathing compressed gas at depth.

 

[chris kippax]

Not sure who's being ignorant but it is a long bow to draw to poo poo something you have not been trained in/experienced.
What if Krack has devised a procedure to control these risks? I certainly don't know if he has or not. He may make a 20ft stop on ascent and exhale??