Unknown Woody From “Dive Talk” DCS and Medical Journey

[catone]

Reminded me also of the fatality of the DAN employee in Florida on SW who got stuck and died and his inexperience diving tight restrictions appears to have played a major part in that fatality

Not to distract from the topic, but the place where it happened it is not a restriction by any stretch of imagination. It is actually a fairly wide open bedding plane, with room for many divers diving side by side. It just pinches down where the line goes, one can conceivably get stuck if following the line in zero vis and panicking

 

[Whitrzac]

Divers get bent. It happens.
There are so many possible contributing factors that there's no way to determine what caused it.

146ft on air, on a sidewinder is a poor choice by any measure.

 

[Tom_Ivan]

Where was it in the video that they said they were using air dill?

 

[L13]

Do you believe he started the dive "expecting" to get bent?

Were the mistakes obvious at the time?


So, if we assume the answer to those questions is no. We shouldn't apply hindsight bias to the event. We need to ask why it made sense for them to behave in the way they behaved at the time and what we can do to prevent that in the future.

I think there are some interesting questions to ask:

• When he first started feeling a "headache" around 70ft did he think that was a possible sign of DCS?

This was unlikely to be DCS.

I simulated the dive in SubSurface (starting from @Tom_Ivan 's work in post #12). At 70 ft he would have been right at the depth that GF transitions from undefined to 0. With total inert gas tissue tension equal to ambient pressure, bubbles would be VERY unlikely to develop. It is much more likely that whatever caused the headache is what caused him to be much more susceptible than normal to DCS, and not DCS itself.

• • Did he consider slowing, returning to a deeper depth, or extending his deco there?
• Why didn't he increase his "setpoint" on deco from 1.2 to something higher?
  • Did the "CNS Clock" lead to him deciding to run less efficient decompression to stay below the "limit"
• Did they have a plan in place to handle diving emergencies?
  • If so, did they follow it? If not, why not?
  • Does Bahamas Underground have a plan for handling diving emergencies?
• Why didn't they immediately start evacuation?
  • Did they think it was something other than DCS?
  • Did they think it wasn't severe enough to warrant evacuation at the time?
  • Did Brian's background and experience as a Navy diver shape his decisions?
• Was Woody conciously aware that he was dehydrated prior to starting the dive?

My big question is why didn't he increase his ppO2 for deco. Though, that likely would not have helped much since he would have cut his deco time to match. Unless getting to the surface sooner might have let him re-hydrate sooner.

 

[crofrog]

This was unlikely to be DCS.

I simulated the dive in SubSurface (starting from @Tom_Ivan 's work in post #12). At 70 ft he would have been right at the depth that GF transitions from undefined to 0. With total inert gas tissue tension equal to ambient pressure, bubbles would be VERY unlikely to develop. It is much more likely that whatever caused the headache is what caused him to be much more susceptible than normal to DCS, and not DCS itself.

Maybe algorithms are just an approximation of a theory that we believe largely reflects reality.

I threw it in subsurface as well earlier today because I was curious.

The drop from 83ft to 140ft on the way out is provocative, in my opinion. Bouncing down to depth could allow bubbles to bypass the lungs and end up on the arterial side. Sort of like have a PFO... That's about a 1.7ata change similar to bouncing down 20 ft after a long deco dive...

EDIT this appears to have been a bug in the subsurface planner.
Some other interesting tidbits based on this he surfaced with a GF high of around 54%
With the time spent at 70ft in someways it resembles a deep stop profile, with a stop at about half the average depth.

If you fit the GFs to the dive, it looks like it ended up being closer to a GF of 27/54.
The green represents 27/54gf's

My big question is why didn't he increase his ppO2 for deco. Though, that likely would not have helped much since he would have cut his deco time to match. Unless getting to the surface sooner might have let him re-hydrate sooner.

If he would have gone to a 1.6 at 70ft and done the same amount of decompression he'd have surfaced as gf of about 27.

 

[L13]

Maybe algorithms are just an approximation of a theory that we believe largely reflects reality.

I threw it in subsurface as well earlier today because I was curious.
View attachment 818732

Could you post your times and depths? that is a much higher fidelity profile than the one I did, and I like to update mine.

The drop from 83ft to 140ft on the way out is provocative, in my opinion. Bouncing down to depth could allow bubbles to bypass the lungs and end up on the arterial side. Sort of like have a PFO... That's about a 1.7ata change similar to bouncing down 20 ft after a long deco dive...

I noticed that too. But did GF exceed 0% before or during the bounce? If not, then there wouldn't be any bubbles to bypass. That is why I want your profile, to look at those details.

Some other interesting tidbits based on this he surfaced with a GF high of around 54%
With the time spent at 70ft in someways it resembles a deep stop profile, with a stop at about half the average depth.

If you fit the GFs to the dive, it looks like it ended up being closer to a GF of 27/54.
The green represents 27/54gf's
View attachment 818734

If he would have gone to a 1.6 at 70ft and done the same amount of decompression he'd have surfaced as gf of about 27.

Overall, looks very much like a quite conservative deep stop profile.

 

[Tom_Ivan]

The video was way too long.

This is a dive incident that has the potential for the community to learn from so I disagree that the video was too long.
Woody didn't go out and decide to get bent that day, nor did he decide that he wanted to make an incident worse. As Gareth Lock teaches, we need to understand why the decisions were made that lead to this outcome.

Even with the benefit of hindsight I can't really see too much of an issue with the dive itself.
-As previously discussed his surfacing GF was pretty low.
-As far a todays tech dives go he also wasn't very deep. However it has been suggested (unconfirmed) that he was diving air diluent. This would put his gas density above the recommended 6.0g/L perhaps this was a contributing factor somehow?
-The drop from 83ft to 140Ft near the end of the dive may well have been a result of the cave layout (is there a survey of the cave available?). They may not have had a choice in this.

I see no issue with them trying to push a restriction at the deepest part of the dive. They clearly have the exploration bug which is totally fine and like before, the nature of the cave determines the dive profile.

As far as the post dive actions are concerned. His symptoms boiled down to "Woodie was very tired". I suspect many of us here on Scubaboard would also try to sleep that off.

 

[KevinNM]

My takeaway from all of this is to start carrying my AMEX card with me on trips. I usually only take one credit card and it isn’t the AMEX since it isn’t widely used everywhere.

Many amex cards have medical evac benefit.

 

[SlugLife]

His symptoms boiled down to "Woodie was very tired". I suspect many of us here on Scubaboard would also try to sleep that off.

During my first couple years of diving, there were numerous instances where I surfaced, had a headache, was tired, moving slowly, and not the best conversation partner. When put that way, it sounds quite bad, but was probably mild dehydration and frequent depth-changes. I've since gotten much better about being well hydrated, taking vitamins and electrolytes, avoiding frequent or unnecessary depth-changes, and taking a slow pace. I also remember my Open Water instructor telling us how it was relatively normal to want to take a nap after a couple dives.

Without having been there, in person, it can be difficult to tell the exact magnitude of what it looked or felt like based on a verbal description. "He looked out of it" could mean very little or a lot, just as my own symptom description above could describe brain-damage or needing some water and a nap.

I don't mean that as a "defense" but rather trying to understand this incident and the lessons that can be learned. Perhaps there's a lot of room for improvement for many of us with being open and transparent about when we feel off, and also with monitoring divers that are feeling off, and what to look for.

 

[rob.mwpropane]

As far as the post dive actions are concerned. His symptoms boiled down to "Woodie was very tired". I suspect many of us here on Scubaboard would also try to sleep that off.

So tired you can't catch your breath, can't take your gear off, can't stand on your own? Stumbling around, nauseous, passing out from being tired?