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How do you spell relief?

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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Didn't I just say that?
Feb 7, 2002

I was just wondering what techniques people employ, if any, to avoid Shallow Water Blackout? :martial


Last edited:
keep cool

I just breath slowly so i dont hyperventilate. I try not to push it too much and stay within my limits, come back to the surface when i get my first contraction.....oups a fish, forget all that and get it!!!!!
Very funny Jay...great minds think alike

Perhaps some clarity on the subject is needed. I've never blacked out personally-- I'm way to conservative. However, as SWB is the bane of every freedivers existence, I was wondering if anyone has been taught or researched SWB avoidance techniques--aside from proper ventilation, time management, and body awareness, etc. I'm currently researching an idea I have, but I don't want to reinvent the wheel. If you don't feel comfortable posting a response here, please send me a P.M.

Thanks all,


Way back when, we lost two spear fishermen in a short period of time. One of the old pros commented that it had something to do with the second season. That was when the risk was greatest. I sort of fell in that range and decided, after many tests, that I could swim steady for 1 1/2 minutes and still make it up from <20 meters. For years I stopped all dives at 1:30, even with a perfect prep, little swimming and down where you don't feel the need to breathe. Now I realise how conservative that number was and that very conservative is the only thing that will work. Too many divers think that they can judge their ability, while on a dive where one small change could make a big difference.
Having said that, I do notice one constant with statics. If the day isn't going perfect, then the heart doesn't slow as much but the number of beats still seems to be the same. If I stop before 400 I'll be OK. Not too practical in the ocean though.
Secret to Blackout Avoidance

There is a great tool for SWB prevention: I call it the ATRC test = ability to retain consciousness test. I thought I 'invented it' in early 2001, but it turns out a few other people have been using vaguely similar techniques.


Chances are that the first few times you try this you will almost certainly black out (on dry land) and crash on any nearby objects (possibly injuring yourself -- it happened to a guy here), so you must have a buddy ready to catch you when you fall!!!

Crouch down (buddy beside you), exhale fully, then RAPIDLY stand up while inhaling RAPIDLY. Continue inhaling to the max, then begin packing your lungs as fast as humanly possible. Count your packs, and pick a number that puts you within a few packs of totally full, and when repeating the test in the coming days and months, always use the same number of packs for consistency.
Once you have finished packing, remain standing (if possible), for about 15 seconds. Then, assuming you were able to remain standing, SLOWLY (!!!) exhale, SLOWLY!, through pursued lips (if you exhale rapidly you'll get a pounding headache).
If you are packing and start feeling light-headed, you may have to crouch down to avoid a blackout.

If your body is in a state which favors retention of consciousness, you should be able to do the test and remain standing, without the slightest bit of light-headedness.

A 'pass' is defined as performing the test and being able to remain standing. A 'B-type failure' is defined as having to bend over to stay conscious, but with no shaking or loss of motor control (B stands for 'blackout' type failure). An 'S-type failure' implies bending over and losing motor control and having a samba.

Here is the scale I use:
10 / 10 = pass with no light-headedness
9 / 10 = pass with slight light-headedness
8 / 10 = pass, significant light-headedness but no danger of having to bend over
7 / 10 = barely pass, vision & hearing fading, almost had to bend over
6 / 10 = finished packing fully, waited several seconds, then had to bend over
5 / 10 = finished packing fully, immediately had to bend over
4 / 10 = half way through packing, had to bend over
3 / 10 = didn't even start packing, had to bend over
2 / 10 = could barely even stand up without fainting
1 or less, fainted from just standing up

This test is the most remarkably accurate way to predict what will happen to you during a hypoxic (borderline) dive. If you fail (6/10 or less), then you shouldn't be getting in the water; you'll be risking your life, because you could blackout from a conservative dive, without warning.

Of course, even if you get 10/10, it doesn't mean that you can dive alone or push it, it just gives you a relative indication that you are in better shape than on days when you scored less than 10.

You'll find that adequate sleep, hydration & electrolyte balance are the most important factors to pass the test.

I have used the test almost daily for one and a half years, observing how I pass and fail based on what I eat, how I exercise etc., and I have developed special routines that put me in a 9/10 or 10/10. I have tried doing deep dives after failing the test, and during those dives I either BO'd, samba'd or had tunnel vision upon surfacing. It has been very accurate for me.

I usually do the test in the morning before going to the dive site, then again before putting my suit on.

Please remember that you must have a buddy watching you or else you could seriously injure yourself! Even with a buddy, do the test away from objects that might hurt you if you fall.

This test measures a huge number of physiological parameters, including adrenal gland function, blood pressure, hydration, cerebral hypoxia tolerance, high energy phosphate stores, nervous system excitability, etc. It is difficult to analyze them all; but the bottom line is that if you fail the test, you're in bad shape for diving.

Eric Fattah
BC, Canada
Re: Secret to Blackout Avoidance

excellent test, i think the doctor made me do it once when i was younger (or it might have been something like it, just without the packing) just tried it got 8/10 by the way

i just have one question

Originally posted by efattah

Chances are that the first few times you try this you will almost certainly black out (on dry land) and crash on any nearby objects (possibly injuring yourself -- it happened to a guy here), so you must have a buddy ready to catch you when you fall!!!

by this paragraph, are you saying that after a few times we will get used to it, and so we can develope a tolerance against blackouts

thanks for the test

Practicing the ATRC test does seem to improve your results, a phenomenon known as 'ischemic preconditioning' or 'hypoxic preconditioning', but the effect is small and to notice it you need to do the test many times a day for at least a week; but be careful, this test is just as stressful to you as a real samba/BO so your nutrition and rest are just as important.

What I really meant is that without paying any attention to your diet, hydration and rest, you are likely to fail in the beginning, until you pay more attention to that.

And VINCE, if you 'just did the test and got 8/10', I assume you didn't have anyone watching! I clearly stated how important the buddy was...

Eric Fattah
BC, Canada
i did have someone watching, i was just about to help my dad with something and i told him to watch me as i tried this and, i specificly said "i will probably faint so make sure you are ready to catch" (well i said that in french, not in english, but you get the idea)

dont worry, after my samba on monday im scared to do anything without a buddy
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Oh the memories...

Eric, I don't think I've done that little test of yours in over 25 years. Though back then as a kid we knew nothing about packing. Our version was to squat down and do anywhere from 5-10 really fast but deap breaths and stand up on the final long inhale. Of course as idiot kids (8-12 yrs old) we were aiming at least for a good light headed buzz. :hungover But I can remember several who would consistently samba or BO doing this. Though we didn't know to call it a samba then either. I can remember getting a bit light headed a few times but mostly I didn't have any trouble with it. I didn't do it often because no one mentioned anything about controlling the breathing after the fact and I usually got those god awful wicked headaches you mentioned. :( Given the considerably less active lifestyle among other things I doubt I'd fair as well today.

I would like to offer a suggestion though for anyone doing this. When you stand up, each hand should be grasping the opposite arm over the outside of your bicep/tricep area. And keep the elbows down and in. Don't try to exert pressure or "hug" yourself, just allow the arms to be in that position. It makes it much easier for your buddy to catch you if needed. They can just reach in from behind and grab you by the elbows or under the arms and guide you down. Also, don't lock your knees when you stand. I'd also suggest a couple practice falls with each other to get the idea. As kids we were lower to the ground and much more resilient. As adults, its a bit further to the ground and we don't bounce as well. :crutch

Thanks for the tool. The first try produced a slight wobble at 11-12 seconds. Just enough to get a reaction from my spotter. Call it just fail, a 6 1/2 (should have bent over). I haven't been training much because of the virus and still have a few days until it runs it's course.
Good lesson.

best wishes
Longfins and I have been pushing with pool dynamic to reach our diving limits and taking notes on how we feel and what our partner noticed in our sub-surface and surface behavior. Over a few months we have been able to develop some reasonably accurate personal "signposts" of when we are near blackout, keeping in mind the day to day variance in peak performance. Speaking of which, I need to go train...have fun

Warm Regards,
electrolyte balance

Excellent post, thanks. I did the test last night and scored an 8/10. I get plenty of sleep, and stay hydrated. My question is- how do you define electrolyte balance and what additions or deletions to one's diet helps achieve this balance? Thanks.
He's not kidding about exhaling slowly -- I did it a little too fast, forgetting to purse my lips, and could feel just the edge of a serious whopper (which fortunately didn't develop).
i did this with a guy who was dressed as superman to catch me. we were listening to the love like woe song(the end of it) and when i stood up a selena gomez song (year w/o rain) came on so just as i was to exhale miss gomez goes ooooh or something i was feeling like being silly because of the effects the test had on me so far i sang it with her through my o mouth and then forgot what was going on due to dizziness and started groovin with gomez ha ha ha. "superman" was laughing his head off and i did too. that exhale was pretty much the end of the test so i finished and instead of passing out got high!
hi. just wondering, do you need to pack for this to work? i ask because i don't pack and have read elsewhere that perhaps it contributes to squeeze?