Scuba and freediving on the same day

[Bob DBF]

1+.



An interesting fact I picked up while reading about this topic a couple years ago:

If you are skilled enough as a free diver (think world-class), you can get bent free diving, completely independent of scuba. It takes repetitive, deep freedives, with inadequate surface rest intervals, but I guess it can be done, and has been documented (first among South Pacific islanders I think).



Best wishes.

Greek sponge divers have been working since the Minoan Bronze Age. Ancient poems
describe the dangerous and unprofitable occupation of the sponge diver. They also mention special special diets, prayers, breathing exercises, weights and tethers for fast sinking and recovery. There is also a Greek folk dance of the bent sponge diver, taking extreme skill to portray the bent diver properly.

Sponge Diver suffering from the Bends - Hotel ELIES & KALYMNOS Diving Center -Kalymnos island Greece - www.hotelELIES.gr

Bob
-------------------------------
Who will not be riding a rock to the bottom

 

[Aigtbootbp]

Wow, not the answers I expected. I was just curious but now I think I will keep my scuba and free diving days separate. I guess it is good my freediving ability is really poor right now or else I might have hurt myself last week.
Thanks for the help everyone, I definitely learned something new here.

 

[charlesml3]

If you are skilled enough as a free diver (think world-class), you can get bent free diving, completely independent of scuba.

I'm sorry but this is in direct contradiction to everything we've ever been taught about how Nitrogen gets dissolved into the bloodstream. Not breathing compressed air = no extra Nitrogen dissolved into the bloodstream.

I need to seem some solid data to support this claim. It sounds more like uninformed hysteria to me.

-Charles

 

[knotical]

I'm sorry but this is in direct contradiction to everything we've ever been taught about how Nitrogen gets dissolved into the bloodstream. Not breathing compressed air = no extra Nitrogen dissolved into the bloodstream.

I need to seem some solid data to support this claim. It sounds more like uninformed hysteria to me.

-Charles

Actually, the air in your lungs is compressed. The deeper you freedive, the more it is compressed (and the smaller your lung cavity gets).
As for that causing DCS, here is just one citation.
Can Freediving Cause DCS?

 

[charlesml3]

That's a pretty thin study. Even they weren't entirely sure it was DCS.

I'd sure like to see a study from DAN to substantiate this.

 

[LeadTurn_SD]

I'm sorry but this is in direct contradiction to everything we've ever been taught about how Nitrogen gets dissolved into the bloodstream. Not breathing compressed air = no extra Nitrogen dissolved into the bloodstream.

I need to seem some solid data to support this claim. It sounds more like uninformed hysteria to me.

-Charles

I would have said exactly the same thing a few years ago Charles, but here is a pretty good study I found on Rubicon by:
Dr Robert M Wong, FANZCA, DipDHM, Director,
Department of Diving and Hyperbaric Medicine, Fremantle Hospital, Western Australia

He does not strike me as the "uninformed hysterical" type


http://rubicon-foundation.org/dspace/bitstream/123456789/6010/1/SPUMS_V29N3_3.pdf

If you start Google searching, using "Taravana" perhaps (what the South Pacific Islanders called DCS I believe) you'll find a lot of references.

Hang around the free diving message boards, and you can talk with apnea divers and competetive free dive spearos who have actually taken DCS hits...

Again, I would have sworn it was not possible, but I learned something new when I started looking into it.

Best wishes.

 

[Cave Diver]

That's a pretty thin study. Even they weren't entirely sure it was DCS.

I'd sure like to see a study from DAN to substantiate this.

I've heard of numerous instances of this happening and I'm pretty sure some of them were posted here on this board. As I recall, your average recreational free diver is unlikely to hit depths capable of causing it, it was related more to those more on the extreme side.

Does DAN cover free diving incidents, or just SCUBA?

 

[LeadTurn_SD]

My understanding (and this is only based on what I've read over the past couple years) is that DCS related to free diving only is very uncommon.

My understanding is that it takes repetitve, deep free dives combined with short surface rest intervals, which puts it outside the capabilities of the vast majority of folks engaging in recreational snorkeling and free diving.

But I've also read several "it happened to me" accounts about world-class free divers and spearos taking DCS hits, plus a few published studies and historical anecdotes to feel pretty sure that it is a possibility that elite free divers need to consider.

Best wishes.

 

[aquaregia]

There's some evidence of deep-diving marine mammals showing up with DCS. They're certainly not using compressed air

 

[FreeFloat]

I both freedive and scuba dive. As far as the combination goes, I have a person rule to never freedive AFTER scuba*, but freediving BEFORE is just fine!

My reasoning for this is simple:

During scuba diving, breathing compressed air, my body takes on a nitrogen load. This load will take a certain amount of time to work its way back out of my tissues. While I have any sort of nitrogen in my tissues, there is a very real risk of recompressing the nitrogen bubbles to a size where they can get through tissues they ordinarily cannot (as pointed out above). Getting a nitrogen bubble on the wrong side of my blood-brain barrier, for example, would wreck my day.

*a note: I consider myself sufficiently done scuba when I have, at a minimum, returned to the "A" column on my tables after my surface interval. The "A" column is the amount of nitrogen load I would be carrying BEFORE I dive. If I did a shallow shore dive for 15 minutes, obviously my required surface interval would be far less than if I just did 3x 20-minute dives to 100'.