Getting Bent Shallow Freedives

[Blueringocto_73]

Ok, I'm going to say that you can't get bent by diving 100 times to 11 feet with 1 minute surface intervals. But I don't "know" that this is true physiologically speaking.

So today I did 20 of those. Don't think it's risky to increase training further.

Why am I doing it? I'm conditioning myself and that's my only motivation.

 

[northernone]

Can't answer from a physiological perspective but from an experiential and historical perspective the odds seem better of being hit by lightening. In clarification I've not been hit by lightening but am not aware of a free diver bent ever from this sort of multi dive profile and have personally done significantly more aggressive apnea training. Google didn't reveal any stories of it happening either.

I'd be interested too (but shocked) if there's medical anomalies that might combine with unfortunate circumstances to result in something so conservative resulting in DCS.

Unsought caution: The other risks involved are much more lethal. Please have an engaged spotter on hand.

Regards,
Cameron

 

[Blueringocto_73]

Yeah that's what I was hoping to hear. I understand the risk of shallow water blackout. Or just simple over-exertion and drowning. Anything else?

I am not hyperventilating because of the risk associated with that.

 

[northernone]

Yeah that's what I was hoping to hear. I understand the risk of shallow water blackout. Or just simple over-exertion and drowning. Anything else?

I am not hyperventilating because of the risk associated with that.

I'm coming at this from two decades of intermittent, unofficial, self coached,
apnea training (not sure how to count it as I started as young as I remember and lost years due to a blown ear drum plus took some time off after a couple death scares and now I'm mainly scuba diving). I'm not a freediving instructor and the only cert I have is from a basic 20m course I did two years ago where I wanted to see how much I "didn't know I didn't know".

Going unconscious for various reasons while underwater or on the surface can be easily fatal. A faint from a drop in blood pressure or hypoxic blackout are the most likely.

More rarely, going unconscious happens unexpectedly in daily life to normal individuals even when they aren't pushing stressing their bodies by breath holding. Easily fatal if underwater or at the surface breathless and alone.

It's far less predictable than we'd like to think. For example it's easy to accidentally hyperventilate through inconsistent breathing techniques and switch off our co2 driven "need to breathe" urge. Or simply over estimate our limits. Laying here typing I can easily black myself out. But I've also has 3 in water unexpected black outs. I was fortunate to float up, face up. (Setting aside my embarrassment to admit this, hoping it illustrates how real and insidious the risks are)

I'm not active in an apnea/freediving community so I feel like this post is incomplete. I hope some other forum members can fill in, correct or clarify on this topic.

Regards,
Cameron

Edit: I've also come close to knocking myself out while freediving. Once surfacing under a diving board, another a log, a third descending onto a rock, 4th ascending under a ledge, 5th ascending under a boat, 6th cracking my head against the wooden float when I gasped surfacing.... Wow, never thought about those stories... I needed to focus on fixing my propensity for going headfirst into hard objects! I'll regain some self dignity with the excuse that most of those were in low visibility (1-3ft) or in the dark.

 

[The Chairman]

You can't get "bent" freediving. Read and reread Cameron's post to get an idea of what can happen. Only freedive with a buddy: one up, one down is the usual protocol. It can be just as dangerous as rebreather diving.

 

[Blueringocto_73]

Yes, thanks for the replies. I've been close to a blackout years ago. Just snorkeling too long and diving. Getting "waterlogged". Diving for cone snails in Hawaii back when there were fewer ecological restrictions.

There is only a spotter at the moment. It's not freediving instruction. In fact I'm not even conditioning to freedive. This is only more preparation for competence in the water for recreational scuba.

I feel more at ease while recreational diving with this type of training. And removing the mask. Donning the mask at depth and clearing the mask on surfacing. Over and over until it's an automatic reflex.

 

[northernone]

Yes, thanks for the replies. I've been close to a blackout years ago. Just snorkeling too long and diving. Getting "waterlogged". Diving for cone snails in Hawaii back when there were fewer ecological restrictions.

There is only a spotter at the moment. It's not freediving instruction. In fact I'm not even conditioning to freedive. This is only more preparation for competence in the water for recreational scuba.

I feel more at ease while recreational diving with this type of training. And removing the mask. Donning the mask at depth and clearing the mask on surfacing. Over and over until it's an automatic reflex.

Makes good sense, being comfortable underwater does wonderful things for enjoying SCUBA diving. Sorry if my post read with too much crusader zeal regarding the risks. All that to say, I'm glad you have a spotter.

Diving for cone snails pre restrictions must have been very satisfying, I can see it would be easy to over do the diving enjoying the hunt.

Regarding your initial question about getting bend to put on this thread for general reference. One thing that may likely get you bend you freediving is if you've got significant residual nitrogen from a preceding SCUBA dive and follow it by repetitive apnea dives.

Glad you're still in the water!
Cameron

 

[Blueringocto_73]

Yes, don't mix the two together too closely. Used to dive to about 15 feet max when I was 16 years old and living in Hawaii. That allowed me to get quite a few cone snails. We did it all solo. Which does involve some risk.

 

[Sam Miller III]

One can get bent by EXCESSIVE REPEATED deep free diving. It was first documented by E.R. (Ellis Royal) Cross in an article in the old stand by Skin Diver Magazine in the early 1960s -- It is called "Taravana"

ER was retired from the USN as a USN diver, had run the "Sparling school of deep sea diving" in Wilmington southern California, purchased a boat "The Fair winds" and set sail to the south seas.

In that era almost 60 year ago diving was still confined to a precious few area and diving travel to distant exotic resorts was about 30 years in the future,

While traveling in the south seas he naturally migrated to and mingled among the pearl divers. There he observed divers demonstrating classical bend aka decompression sickness symptoms. He investigated and discovered the victims ad made repeated deep dives every day in search of the then only commercial product pearls.

The natives called the affliction "Taravana" which translated to "fall crazy"

You have not been diving deep enough or of long enough duration to become bent - and GOK what you have or suspect you have.

I have known two former dive buddies who were both avid SCUBA diver and spear fisher men who after a day of deep diving went free diving and became bent which required RX of a chamber run.

The first one had did several deep dives in search of California Lobsters and his dive buddy had seen some late season WSB - they both grabbed their Spear guns and went in search of WSB. He as noted as a deep dver and worked the deep reefs and was bent--he knew better but a WSB was the king of spearfishing in those days

the second was a pioneer LA Co UW instructor (long before PADI & the other instructor programs appeared) had completed the Catalina check out , did several SCUBA dives, then at the end of the day went free diving with some of the students for the then plentiful abalone at Catalina island. on the return trip he began noticing classical bend aka DCS symptoms and checked himself into the local chamber for RX--he was bent

It can happen after a dive of bubble blowing followed by free diving

Suggest that you goggle Taravana

Sam Miller,111

 

[MAKO Spearguns]

Yes, as Sam indicates, freedivers can get bent. elite divers doing multiple deep dives must be wary of this. They typically take longer surface intervals than would be required for simply co2 recovery.. on the order of 8 minutes or more. It is a non issue for shallow snorkeling.

Diving alone is a much bigger concern than the bends for normal freedivers. dive with a buddy.

Dano