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Empty Lung Dives

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.
does anyone know if anyone has done any deep dives using this tec??

Does anyone know how much 02 is absorbed during a dive ie when the lungs are partialy compressed untill fully compressed?
Just wondering if a really big breath makes that much difference.
Is it more the time spent deep breathing before the dive that is doing the good ie storring o2 in the blood???

(as you can see i'm no scientist so i'm sorry if i'm asking stupid questions) :confused:
Originally posted by Alun
as you said, there is less surface area with empty lungs, but furthermore, a greater proportion of that surface area is non-alveloar, which should mean that diffusion is even slower.

Do you know of any medial articles that support that? I'm getting sick of trying to access databases...:duh

And while it is true that a full lung dive means a greater initial concentration of oxygen in the blood (increasing during descent) it doesn't imply that more oxygen will be "sucked" out of the blood during ascent.

Consider two divers of identical breath-hold ability and blood volume, one of whom has dived with full lungs to 10m and one who has done a negative dive to 10m.

Obviously the negative diver will have less bottom time. But lets assume that the dives were timed so that at a given point the two divers have the same concentration of oxygen in their blood. According to Henry's Law the two divers will have the same amount of oxygen "sucked" out of the blood as they ascend.

hmmm. Why can't humans be spherical and live in a vacuum? :D
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>Henry's Law states: The pressure of the gas above a solution is >proportional to the concentration of the gas in the solution.

Does this law apply to the O2 in our blood? If I understand how the lungs work, most of the O2 in the blood is bonded, not in solution. On the few times that I experimented with the saturation meter, the figure stayed in the high 90's while I used up lung O2 first. After a few minutes the meter started down and I presume that blood O2 'tracked' lung O2. This few minutes would seem to violate Henry's Law or am I guilty of fuzzy logic?
I met Jim from Fiji the other day. He was the first english language student of Pinpin as well as a good friend of the Sub. I've never met the Sub but I know he doesn't have any sponsers and I heard he is not looking to dance with the "world record" crowd. (Although he has beaten many with his team.) He has a system where he free falls with weights and get's crancked up via wire from the boat. It's diffrent from any catagory we have ever heard of. I'm not sure the exact depths he has gone but I heard he has swam 200m underwater.

Anyways the Sub told my friend Fiji a training secret. He said the most effective training is to train with empty lungs. When you train in a pool, exhale. Whatever traing you do, do it with no air in your lungs. He also said that empty lung dives to warm up will make the mamilian reflex to come quicker, up to 30min. Jim said do 3 empty lung dives and the reflex kicks in.

So far I've found this traing true and has many benefits. At first it was a bit weird to get used to but I highly recommend it. To warm up I bring just enough air down so I can equalize without any problems.

It has helped me to get to know my body more. It also gave me a lot more confidence when I'm diving with a full lung. I think it makes the muscles get used to working with no oxygen situations so when you are really out of air you're used to it. It also makes the muscles work like a super star when you do give them oxygen to burn.

I will add that this training is very dangerous. I know I'm asking for a black out when I do this. I mean I really am asking for it. One thing Jim add was what Pinpin told him. It was to get to know what it feels like to have a black out on land. This way you have a better idea of your limit and you know the feeling underwater. Please let your buddy know that you are going for an empty lung dive. Make a hand signal so that your buddy understands what you are about to do. Have him swim next to you when you start. This stuff is no joke. You will sink like led without air so stay shallow when you begin. It's kind of like racing a sports car without a seatbelt.

If you are going to do this, please please please be careful. Otherwise I'm going to have to fly over there and chain you to a tree so you can't go diving.
Originally posted by caymandiver
Anyways the Sub told my friend Fiji a training secret. . Jim said do 3 empty lung dives and the reflex kicks in.

This technique is not a secret...it's been discussed many times over the last few years here, and a lot of divers use it for "quick dive mode" Especially the cold water guys :)
Have a look at this : http://www.2james.net/ey.html

Erik Y.

I'm sorry about that. :duh It was the first time I have heard of empty lung dives.

I read your post. Really great stuff. I've also found that taking my mask to the forhead for a few minutes really helps. I've noticed that taking out the snorkel makes me feel more natural in the water.

I'm curious, do you guys see any sharks up in Canada? Any shark spotting around the coast?
No worries amigo, no offence taken at all....I certainly didn't invent it! But I was doing it before I heard about it. It seemed that logically the effect would be to simulate depth, and the nice by-product was the "quickening".
We get six-gill sharks and dog sharks on the west coast. During El Nino a few years back there was talk of a Great White siting off Victoria.
Erik Y.

How about orcas? Do you know of anyone diving with them and their experiences? You must have some up there due to the cold waters (?).

Out here in Tahsis, on Vancouver Island, it is a hot bed for six gill sharks like no other place, supposedly. Better than Hornby Island I am told. There is actually a location just out of town here that is called Shark Point. I saw the dive shop states that beyond dogfish and six gill sharks, even Blue Sharks have been spotted at this gathering location of sharks. It is right next to some of the best diving in the area as well. I can not wait to check it out soon.

As far as orcas, I wouldn't dive near them on the west coast of Vancouver Island, since most that you would encounter are probably transient orcas. However, in the straight of Georgia there are many resident populations and I have heard of near encounters with divers. I think you would really only want to dive near them, if a guide or expert is aware and knows of the pod you are encountering.
Has it ever been reported of an Orca attacking (and therfore most likely killing) a human?
The problem is that not much evidence would be left...
In Norway they dive with orcas but as you say Tyler, with a guide who knows the signs and can determine the safety of the dive.

Michael, not necessarily there would be no evidence. I saw a TV documentary of a goup of orcas separating a (whale) calf from it's mother and attacking it. The curious thing is that they were very exclusive of what they ate, only the tongue! apparently it is "haute couture" for the orcas and they left the rest of the body alone.

What a waste....:(

The only confirmed attacks by orcas that I am aware of, have been by animals in aquariums. They can usually not determine if the animal was just playing with the trainer, or actually intended harm. What I generally use as my evidence against TRYING to interact with an orca, is that in the wild even dolphins have caused severe harm to humans and they are quite small and share a similar countenance as orcas. There have been known aggressive behaviours by dolphins, yet some of the sever accidents were not known to be aggressive. Either way, an orca is merely a large dolphin that can be very excitable I believe. Just trying to play with you, it could unintentionally destroy you in seconds.

If you have ever seen the footage of whales hunting seals along the shorelines, you know what I mean. They toss the seals around, and up into the air, like rag dolls. Watching them hunt a bull sea-lion, they bash the thing into unconsciousness, or weariness, with their huge tails. These are transient whales though. Remember to look up the difference between a transient orca and a resident, they may as well be two different species of whale, due to their behaviours. Basically, residents almost solely eat fish.

Adrian, I saw the same show I think, was it about Montery Bay or something in California, where the Gray whale and her calf tried to cross? My memory recalls they ate the tongue first, but continued to consume the rest of the animal?

By the way if you like sharks and orcas, check out my post on an encounter with porpoises here in Tahsis:


or a six gill shark encounter:

http://quietdeep.com/scripts/site/writings.php (go to "In Memory of Grandpa")
Adrian, maybe that whale cub had a smart mouth. :)

So there are local Orcas that might be more friendly to the surroundings, and transient ones that are of more predetorian character...
I wonder what you can do if your ran into one far from the shore/boat.

I think I saw some long time ago in a doctumentry about Ocras how they killed a GW shark, I think it was because they had a cub around...
I'm not sure if my memory is correct. I was doing somethig else while national georgraphic played in the background...
Anybody heard of that?

Tyler, I've read the porpoise story (and saw the videos) already.
You are very lucky. :)
I asked someone here once before, but I still can't tell the difference between dolphins and porpoises, I don't even know why they need different names...

I'll read the shark thing as well.

edit: Woo! 500 posts. maybe I should slow it down...
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That was the same show Tyler. I also saw the seals being tossed around as if they were the lightest thing ever. It was really impressive and quite sickening as well, knowing what was happening to them. Here's where I read about diving with orcas:


Don't slow down Michael!

Empty dives, I think, are great, but it is a technique that merits great attention and respect. I could not see how they would minimize the potential for SWB. I agree with those above that they probably significantly increase the potential for SWB. Just recall that it is the build up of CO2, not the depletion of oxygen, that triggers that painful, burning urge to breathe.

Still, Ditto to Cayman, I've used empty dives a lot in the past in 12 foot or 4 m pools. I've done it to improve my oxygen efficiency rather than to develop CO2 tolerance. I never do it for more than a minute or a minute and a half since I have felt dangerous sensations before. When I did it repeatedly, I could feel my oxygen content in my body falling and you feel very tired after this. I find it remarkable how better you do get to know your body with these. Better to do with a buddy, definitely, to carry a watch, and to know your body's limits and responses to make sure you never drown.

Like Cayman, for the nose and ears, I actually don't usually do a completely empty dive. Usually I take a very small breath, that is, barely enough air, that I can use to clear when I hit the bottom.

I've also used them to test fire spearguns in my pool whenever I'd forgotten my weight belt and didn't feel like fetching it, but this is a lame excuse! hehe
Train safely,
Both scenes, the Orcas hunting a gray whale cub and playing "seal polo" that some seem to describe are at least on the "blue planet" DVD. Propably the same scenes are in a lot of documentaries, but that DVD series is worth getting anyway :)

Old thread, but just caught it...
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Orcas are very big, very smart, and very fast. As I can't tell the difference between an excited orca who wants to play and a grumpy, irritable orca I would give them a very wide berth just for good measure. It's also important to remember that orcas get around on the beach suprisingly well also.

FRC or empty lung diving has been around a while. I have heard that consistant FRC raises your hematocrit levels, even to the point where testing by an "official" body will get you tagged for substance although I don't know that for a fact.

Folks have posted several time about air expansion in the lungs sucking the oxygen out of your blood as the pressure drops, but has anyone actually tested this? It would seem to me that we utilize such a small volume of oxygen in air itself I would wonder about how much could be a "pulled" back out. From my own experiences I would think the greater risk of SWB on full lung would stem from the lungs pressing on the pulmonary arteries and decreasing blood flow to the brain. Especially since we normally pack as much as possible before a deep dive, and it's easy to get light headed just packing heavily when dry.

In either case I avoid trouble by simply starting my exhale @ 10m or so when surfacing. Seems to help minimize the issue whatever the cause for me.
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Sucking 02 out of the lungs on ascent, does it actually happen or does the idea just sound right?? Good question.
Eric F posted not too long back that no one had ever demonstrated the effect. Shortly after that, I saw an abstract of some physiology research on skilled divers that centainly indicated the effect was occuring, but it did not prove it. The idea seems logical to me, especially since a potential SWB victim is already operating on the edge, wouldn't take much to push him/her over. I've also seen the idea of expanding lungs on ascent pushing on arteries, reducing blood flow to the brain. This also seems logical. Again, it would not take much. I suspect the real cause of SWB is a combination of both+. Either way, I'm with Scot, slow exhale near the surface on ascent.

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