over packing? initial vertigo..

[fishimani]

Hey everyone, had a quick question for some of the more technical freedivers.. My breathe up is always double what my bottom time will be (usually a 6-8 min surface interval) Standard breaths until my last three which are deep, then an inhale (i'm sure there is a specific word for this) which starts with the stomach and then the upper portion of the chest... on top of that i snorkel pack 10-15 "gulps" of air before my descent. As soon as i start to descend my vision gets grainy and sometimes i have light tremors.. like shivering ... until i clear 30 feet .. then the rest of the dive is fine... no samba, no leg fatigue.. no dizziness... nothing. Any guess? I think it has to do with over packing... when i shorten the amount of "packs" all of the symptoms disappear. Anyone have similar issues? Thank you in advance.

 

[Apneaddict]

Sounds like you are VERY near blackout.

Some people can black themselves out just by packing, as the lungs expand and constrict the aorta.

It sounds like you're OK at the surface, but by duck-diving you're putting pressure on the vessel and nearing blackout.

The pressure is alleviated when you're vertical again and down 10m where your lungs are 1/2 their surface volume.

Russian roulette. I wouldn't pack nearly as much any more, if at all - 10-15 x through a snorkel isn't a lot.

You can try packing at home on your bed and get yourself to blackout simply by packing. Or you could pack your regular amount and while lying on your side do a faux duck dive to see if you mimic it or actually BO.

Either way, I wouldn't pack I I were you. If you blackout at -2m, you WILL float back to the surface, but not likely face up.

I know a smallish guy with a huge lung capacity and because there isn't a lot of room in his torso for things to move around when he inhales at the surface can easily black himself out by packing at will.

Not worth the risk while in the water.

Dive safe.

 

[Mullins]

Packing blackouts aren't great, but they're hardly Russian roulette either.

 

[Apneaddict]

His profile says he's a commercial spearo. Those guys typically dive alone / without safety divers / spotters / buddies.

I'd say if he's diving alone and he's getting these feelings below the surface... It's a nasty gamble that I wouldn't take.

 

[Mullins]

Even alone, the chances of it turning out badly would be slim. I suppose you might get a mouthful of water when you came around.

 

[Apneaddict]

Imagine if he weighted himself to be neutral at -10m, blacked out from packing and came to on the bottom at -15m with no recollection of how he got there or how much time had passed!?!?

That's be enough to freak me out for life I think - not sure I'd ever dive again! LOL

 

[Mullins]

Yeah posssssible I suppose, but packing BOs don't really play out like that. They're brief and subside quickly as you get deeper. You're generally disorientated and take a second or two to remember what you were doing (ahh yes, diving... now which way was I going? And what country am I in - is it legal to shoot that fish?) Nothing like a hypoxic BO. I've had big sambas on the way down in CWT and half way down the first length in DYN. A couple of actual BOs in DYN and they were total non-events. Blow some bubbles, wake up, realize what happened, swim back to the wall and start again.

Fishimani, eating before diving helps prevent packing BOs. So does flexibility - and of course not packing so much.

 

[Simos]

Yeah posssssible I suppose, but packing BOs don't really play out like that. They're brief and subside quickly as you get deeper. You're generally disorientated and take a second or two to remember what you were doing (ahh yes, diving... now which way was I going? And what country am I in - is it legal to shoot that fish?) Nothing like a hypoxic BO. I've had big sambas on the way down in CWT and half way down the first length in DYN. A couple of actual BOs in DYN and they were total non-events. Blow some bubbles, wake up, realize what happened, swim back to the wall and start again.

Fishimani, eating before diving helps prevent packing BOs. So does flexibility - and of course not packing so much.

Interesting Dave - why does eating before diving help packing BOs?

 

[Mullins]

Blood pressure, presumably. Makes a big difference.

 

[watts]

If you have to pack you could also try packing slower.
Hydration makes a big difference too.