Taboo Decompression

[jadairiii]

What rjack321 said is right on point. My only addition is that you are making a medical decision at that moment, and I will assume, you are no doctor.

There are other medical "conditions" that can mimic a hit. And recompression could be the worst decision you could make.

But, do what you want to do, you're alone (on this hypothetical dive), so its not like your decision will risk anyone else's wellbeing.

 

[boulderjohn]

It is pushing me toward the assumption that in-water recompression is not such a bad idea for remote areas and certain situations.

As I said in my earlier post, attitudes about IWR have shifted significantly in the last decade. It used to be pretty much a flat "just say no," but today we have more of an agreement that doing it well under certain circumstances is OK. The "certain circumstances" does not usually include being solo. If things get seriously worse during the IWR (and they can), you will want some help.

 

[Underwater Tourist]

This will answer all your questions:

 

[happy-diver]

See as simon says The key benefits very early recompression"
So as my hair pigment decreases, and dive fatigue increases
I breathe a high oxygen rate and carry 50%, and dive safe so
I suggest my dives are happy approved recompression dives

 

[100days-a-year]

Disclaimer, please do everything to prevent DCS so this post is moot. Solo, remote and extreme profiles are unnecessarily risky.

As someone who has actually done IWRs on people before on a remote boat instead of reading about them here are some tips.
1. Use a FFM
2. Use a very sturdy down line and attach yourself to it so you can't descend deeper than you are comfortable with.
3. Try to use the shallowest depth you feel comfortable at.
4. We have also had success using 50 to 80% to go a bit deeper to ensure bubbles were recompressed.

P02 is up to you, solo and remote I'd stay below 2.0

DCS happens. Sometimes well within NDL, pretending everyone has first world access to immediate medical care and a chamber is flawed thinking.

 

[rddvet]

You seem to be stating that oxygen on the boat is equivalent to oxygen at depth?

Youre completely missing the main point he was making. His point was rather than trying to fix it yourself underwater where nobodys there to help, you're better off breathing oxygen on the surface while waiting for help to arrive or while you drive back to the dock. The main point is finding the safest way to get yourself appropriate help.
If you're doing deco dives solo off a boat far enough away you can't count on the coast guard getting to you or you getting back to shore, then you should not be doing those dives. That is the complete opposite of risk mitigation.

 

[Jcp2]

Youre completely missing the main point he was making. His point was rather than trying to fix it yourself underwater where nobodys there to help, you're better off breathing oxygen on the surface while waiting for help to arrive or while you drive back to the dock. The main point is finding the safest way to get yourself appropriate help.
If you're doing deco dives solo off a boat far enough away you can't count on the coast guard getting to you or you getting back to shore, then you should not be doing those dives. That is the complete opposite of risk mitigation.

The analogy would be BASE jumpers versus regular skydivers. The risk is the whole point of the exercise.

 

[Eric802]

I've recently seen a few more examples of people being bent (within 4 minutes of surfacing) and just immediately going back down to around 20-40 ft, on nitrox and being "All Better" in
15 minutes. It is pushing me toward the assumption that in-water recompression is not such a bad idea for remote areas and certain situations.

Which begs the question, would they have been just as well off getting on 100% 02 at the surface? I've read plenty of stories about folks feeling symptoms, getting on 02 as the boat races back in, and feeling fine by the time they get to the dock.

 

[boulderjohn]

Which begs the question, would they have been just as well off getting on 100% 02 at the surface? I've read plenty of stories about folks feeling symptoms, getting on 02 as the boat races back in, and feeling fine by the time they get to the dock.

The value of pure oxygen, whether on the surface or at depth, is the fact that it has no nitrogen. Pure O2 on the surface is very valuable for that reason--by itself, it came close to fixing my DCS. Oxygen does not have any less nitrogen at depth than it has at the surface.

The value of depth is what it does (no one can say for sure) to the DCS problem itself--mostly squeezing down bubbles. I have done a couple minor IWRs in cases where a diver was symptomatic as soon as he reached the surface, and the symptoms disappeared immediately upon reaching only 20 feet, long before oxygen itself would have had any benefit.

 

[OTF]

Where do we draw the line between true "in water recompression" versus surfacing with skipped deco but immediately returning to depth to finish it?

When I think of IWR I picture a process undertaken perhaps tens of minutes to hours after a dive, after becoming symptomatic on the surface. Dangerously high PO2s, FFM, team support.

Would we still call it REcompression if a diver skips deco due to an emergency, sorts the problem, then quickly re-descends to complete an extended schedule of stops? Perhaps not even knowing if they're symptomatic? It's my understanding that depending on exposure there is a short window (like 5 minutes) where this can be feasible with minimal bubble formation. I recall most agency training material recommending to stay on the surface and NOT go back down in this scenario. But if I blew my stops I'd strongly consider it. Someone like @Akimbo can correct me if I'm wrong on the following - but don't commercial divers sometimes surface to 1atm before quickly getting in a chamber for deco? Or maybe that was a historical practice that isn't cool anymore.

Another question - is it reasonable to think that a "mild" in water recompression is better than nothing and perhaps a middle ground in terms of benefit and safety? Say a long dive to 20ft on O2 with a very slow ascent rather than the extreme PO2s of an in-water table 6. Theoretically better than staying on the surface, but perhaps not deep enough to crush bubbles in a serious hit? Worth doing before transport to a chamber? Just asking to move bubbles to worse places and delaying more effective treatment?

The analogy would be BASE jumpers versus regular skydivers. The risk is the whole point of the exercise.

As a tech diver who also participates in some unrelated "extreme" sports I think this is a fascinating point of discussion perhaps worthy of its own thread. To me big or solo dives are a polar opposite experience from say dropping in on a huge halfpipe. Diving is methodical, meditatively calm, precise, cerebral. There's no "send it" and no adrenaline rush. Risk MITIGATION is the objective, not pushing limits for the thrill of surviving some crazy feat. However I do know other divers who are chasing big dives for the rush or machismo. I worry about those people. Wish they would get a skateboard.