when do yall blackout?

[bikenlax]

i know your unconscious and cant remember squat, but at what point am i pushing the limits? i know it all depends on my body, but when do you guys feel that you reahc pass-out level?

[rslomkow]

I have had the good fortune, or cautiousness to never get very close to blacking out in the ocean.

In my teenage years I have done it twice in a swimming pool (unsupervised and with friends). We used to do underwater swimming contests.

I have the good fortune of seeing lots of stars (black & white static at the edge of vision) before blacking out for at least a couple of seconds. And watching my vision tunnel to blackness. But lots of people just go black! and suddenly!

Doing 200 yard (Amercian swimming pools are 25yards [23m] long) underwater swim races I have blacked out and floated up.

Lots of factors change when this happens all the things that make it harder to hold your breath. Activity, breathing, neverousness, diet, getting shocked by somehting.

[naiad]

I don't get any reliable warning. Sometimes there is a feeling that the urge to breathe fades away, or becomes a nice feeling that I don't want to stop. Then I know that I am close to the limit. Sometimes there is no warning at all. I have never had any disturbances of vision.

There are certainly lots of factors that affect how long you can hold your breath. I have hardly ever blacked out doing my longest times or distances. It has mostly been because of doing something different from usual, which I am not used to.

Lucia

[Huw]

only had one blackout, was a dry static. The urge to breath sort of subsided and i began to feel a tingling sensation in my fingers and toes. I thought i was fine, and i didnt feel like i needed to stop... i woke up about 10secs later

Huw

[Soul Deep]

I don't, and best practise is to make sure you don't get near that point! Freediving is about having fun, and the calm and peace it gives. Always return before your get that uncomfortable urge to breath; then train to extend that period. That way you never get black out

[cdavis]

There are several descriptions under, Frediving training, safety, and another detailed account under Freediving Stories, "Lessons learned in the Bahamas - An intimate account of our most dangerous enemy".

Personally, I've never blacked out, but at about 17, I had several instances of tunnel vision, loss of color vision, etc. Real close to BO, associated with fast repetitive spearfishing dives and hyperventilation. If it hadn't been very shallow, I probably wouldn't be here.

Connor

[bikenlax]

ok thanks guys. im not underwater right now, and am really not a freediver too much. at all. im looking to better bottom time for spearfishing, when im not using scuba gear. ive not quite gotten that close, only too the point where my hands lock up and its hard to move them, if i can at all. i was just wondering if i was close ata all, and how muchfurther i could push it.thanks

[tylerz]

First, I would suggest that the feelings prior to a blackout are the same as the feelings prior to a LMC/samba, however the mind often tends to be in a different state before each. A LMC/samba tends to happen when a diver has already determined they are ending their static or a dive happens to complete just shy of a severe O2 depletion. Blackout tends to happen more often when the diver is still focused on holding their breath, which tends to lend to more focus on what their sensations were until the last moments. So, further in my response here, any references to blackout also refer to LMC/samba. And if a person has had an LMC, then in my mind they have essentially had the experience of reaching blackout. During LMC one can completely lose consciousness without exhibiting a significant external loss of control such as we associate with blackout. And for this reason I see it as rather pointless to differentiate between them in the regard of assessing one's ability to control their dive to a safe range.

On an 8+ minute static, I have the urge to breathe half way, or less, through the static if I breathe up one way. If I breathe up another way I may have the urge to breathe 2/3 of the way through. I have never been able to get the urge to breathe to come later than 2/3 of the way, however, with enough modification to my diet and other modifications, I am certain it would be possible.

A dive is much more variable than a static however. Some dives have half of the dive spent more like a motionless static and half as continuous exercise, others are continuous exercise all throughout, some are on full inhale, others on less than full, some half sporatic motionless periods throughout the dive interwoven with exercise. Therefore a simple rule such as surface when you feel the urge to breathe, or surface before feeling the urge to breathe, is not very effective for a wide range of divers and diving styles, in my opinion. It also has the tendency of supporting peoples' inclination that they will feel the urge to surface on time, which for some people and for certain states of the body, can come in an unreasonably close proximity to blackout or not at all.

I believe that, unfortunately, if a person has not had a blackout/LMC then unless extremely experienced with numerous attempts at pushing their limits, they are unlikely to have solid grounds to comprehend for their body when they are close to blackout. The body can go through so many untoward feelings leading up to max apnea abilities, that one could determine all of them were the sign of the end, if they never see the pattern which actually arrives consistent with the experience of a blackout/LMC. These patterns may be person specific. I have not heard of a consistent and thorough explanation of a common feeling that people experience just prior to blackout. I believe part of the problem is people not wanting to admit they have had blackouts/LMC, which stops us from gathering the details of information related to it.

Hopefully this thread can gather more people's experiences, so, even those people who can't find a pattern, saying so is also a valid piece of information.

So, from myself, my blackouts/LMC's were precursored by a long time spent feeling "this is challenging already". During my two dive incidents, both times were spent in this feeling from the bottom all the way to the top, 45m and 61m. Nearing the end of the dives, I did not experiences a change in feeling other than more certainty that I was pushing the edge eventually degrading to lost memories and blurry memories with no feelings. My many dry statics ending in LMC, a dynamic, and a wet static, have been much the same, except another wet static while recovering from sickness just felt extremely brutal like trying to do a static after sprinting. From 3:00 to 6:00 I was pounded with CO2 headache, heat, and contractions. During all statics I feel my extremeties become heavy and buzzing long before the end. I have nothing I currently associate with "the end is nye".

Good thread, hope to see more data.

[Evita]

Originally Posted by Soul Deep

I don't, and best practise is to make sure you don't get near that point! Freediving is about having fun, and the calm and peace it gives. Always return before your get that uncomfortable urge to breath; then train to extend that period. That way you never get black out

I totally agree! Well, 95%.

I have never BO'ed or done the samba and I hope to hell that I never will!

Hoping is not enough, though. I make conscious choices in every dive session to surface in time, and even well before my limit. Of course you have to get close to your limit to know where it is. Just don't jump into the abyss willingly. I don't understand the ones that do.

Like Soul Deep, I try to extend the comfortable period. But I also try to accept the fact that for me, the urge to breath just IS uncomfortable, but it's something that I can stand for a while without shutting down. So what can I do to deal with it longer mentally, when it finally sets in? It's a balance - don't surface before you need to, but do surface while you're in control.

Of course I am just speaking as a novice here - having never lost it, I don't know what it feels like. And feel free to point your fingers at my purist philosophy when I finally do have my first BO or samba

They are dangerous exactly because you cannot predict when they will come. The factors mentioned all play into it, and the limit will be different on different days. So your question is good, because you focus on how it feels, instead of how to calculate it in general. Being aware of how you feel throughout the dive is probably the only way of avoiding a BO.

Feelings also change, though. When I started doing static training, I felt that a tensing of back and neck muscles signalled the end. Now the signals are different. So monitor yourself closely and be aware of changes, noticing when the changes happen the same way twice. Tylerz' idea of patterns is probably very helpful.

For me, I like to have a buffer, and surface well in time. It feels good to dive within my limits and pushing them in front of me, not crossing them... so far

[matrixed82]

I've had a near blackout and a samba, both while doing wet statics. I believe that purging a little too much might be the cause.

The first time it happened was when I started to include purging before statics, I didn't realize that by overdoing it I could really eliminate much of the urge to breath. Right at the beginning of the hold I experienced some of the tell tale signs of having low CO2. My fingers were very tingly, up to my knuckles and I was a little dizzy. At that point I had never experienced a blackout so I figured I would just go ahead with the hold and I would know when to come up.

Needless to say that this static felt really comfortable, I only started to feel the contractions past 4 minutes (at that point I usually got them near 2:30) even though my buddy said I had fluttering contractions or something like that that started around 2 to 3 minutes. The contractions were there but they were not uncomfortable, it wasn't like I was fighting them. All I remember of the end of the static is that I was listening to some people taking around the pool, I was able to signal to my buddy I was ok. Eventually it felt like the contractions had left completely and I could just stay in that state, without breathing forever. It was like falling asleep. At that point I was kind of out of it but still able to respond to what my buddy was saying. He asked for a signal, I gave it to him. He told me to put my hands on the edge of the pool, I did it. He told me to come up, I did it. The last thing I remember hearing is 'come up' .

I was told that I took my head out of the water but wasn't breathing, my buddy just took off my mask and only then did I start breathing. After a few breaths I was alright but had no idea I had just had a near black. I just thought I did a great static and it felt good.

My second experience was during the PFI clinic and resulted in a samba. My purging was much less aggressive so the start of the static felt much better, I was not dizzy but my finger tips were a little tingly, as they usually are. It felt like a usual static for me, I think the contractions started around 3:30. I remember having to really fight the contractions beyond the 5 minute mark. I decided to keep my eyes open this time in the hope of getting any signal to come up before its too late. I did, my vision was a bit greyish and blurry, kind of like when your looking out from a speeding car. I thought to myself "I should really come up now" but I wanted to wait another 15 seconds to reach 6 minutes. The contractions were getting very strong and bubbles blew out of my mask twice, then I was told to grab the edge of the pool and come up. This time I remember everything pretty clearly and I had a pretty bad shake. I kind of fell back once I took my head out of the water.

Given that I've only had two near balckout/lmc experiences and they were quite different I haven't figured out any specific patterns that lead to a blackout for me. For this reason I agree with Tylerz statement,

I believe that, unfortunately, if a person has not had a blackout/LMC then unless extremely experienced with numerous attempts at pushing their limits, they are unlikely to have solid grounds to comprehend for their body when they are close to blackout.

Even after reading about signals that lead to blackout here on DB, I had no idea it was going to happen to me when it did. Even if you play it safe and come up at the first urge to breath you could still be susceptible to blackout. You may never feel the urge. When I had a near blackout, I would have just stayed there motionless in a very relaxed, comfortable state if it were not for my buddy who told me to come up.