(5/01/05) Diver missing in Florida

[pickens_46929]

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If anyone has more current info to correct this post please do so....
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This info creates more questions;

If a diver is breathing Nitrox at a high rate, will it impair a diver?

Why didn't this diver ditch his weights?

Even with a light wind, I wonder what the waves or chop was like?

Been out there with 5 ft. swells and it wasn't fun.

As for the two questions...

1) Nitrox actually helps and 30% (EANx 30) is appropriate for the Grove. Many do it on EANx32 which pushes the PO2 level up -- ok if you watch your depth but it's easy on the Grove to plan for 100 ft. and end up at 110 ft. So can't say for sure, but this doesn't scream as a factor to me unless he wasn't Enriched Certified. Not being Enriched Certified and using EANx30 on the Grove would be something I'd be concerned about!

2) As for ditching weights, this is one of the more common things found on the DAN accident analysis ... something like 65 to 70% *DON'T* ditch their weights or other gear. An instructor told me the story recently of a diver who died in a cave. He had a large (8"x10") slate which he wrote his last will and notes to his family on... covered both sides. My instructor's comment? If he had enough air to write *that* much, he had enough air to get himself out of the situation he was in.

A tech diver in North Carolina last year did a back entry over the side of the boat, forgot to connect his inflator hoses and drown. Still had his weights on and air in tanks.

Dave

 

[pickens_46929]

I've dove it 3 times and have a healthy respect for it. I think the dive is more dangerous at the surface then uw.

That first and last 15 ft. of the dive on the Grove can be worst part.

Other big problem I've seen is current below where people either don't use the wreck to shield themselves or don't consider they are going with the current initially, then struggle to get back to the line when they return.

Dave

 

[pickens_46929]

See their website. NItrox tanks (30%) available for rent. The explination I got when I asked the operator we were on why 30 and not 32 is b/c some divers lose track of their floor. Like I said I have not dove with this operator but I sincerely doubt a PADI dive center would intentionaly let divers down past 1.4 ppo2 for liability reasons.

http://www.itsadive.com/Dive_Spiegel_Grove.htm

When I first did the Spiegel Grove on Nitrox, that's exactly what I did to add a margin of safety. My planned depth was 100 ft. with max contigent depth of 110 ft. So EANx32 was cutting it pretty close. Opted for EANx30. Since then, I've done the dive on EANx32 now that I'm more experienced with Nitrox and know my own reactions and capabilities.

 

[pt40fathoms]

I dove with It's A Dive in the first week of March this year. My dive was done with 30% Nitrox, and their reasoning for supplying 30% when I asked, was that at 130 your PPO2 would be too high with the standard 32% mix. The current at that time was high, and our 15-foot safety stops had us hanging on tight. My other two dive buddies and I decided to stay only the lee side of the wreck when we reached it to be out of the current, all three of us were certified technical divers, as well as DM's or higher. I would dive with It's A Dive again without hesitation, and their choice to supply only 30% to divers who want Nitrox is an indication to me that the safety of their customers is foremost in their minds. This accident has caused a lot of grief and hardship to the family and friends of the victim, but also to the dive operation and most especially to the captain of the dive boat who had to experience this first hand. My heartfelt condolences is extended to them all.

As has been pointed out earlier, the DAN annual reports clearly indicate that upwards of 70% of all divers who drown, still have their weights on. The doctor who perished made his life’s calling to save lives. The highest honor you can afford his memory is to learn from the tragedy that took place. If you are in trouble in the water, remember this if nothing else. Your gear is expendable, you are not!

 

[mempilot]

I'll be diving on the SG on June 5th. My gas mix will be 30/30/40 trimix. Ean30 gives a MOD PO2 of 1.53 at 135fsw, but a TOD PO2 of 1.39 at 120fsw. I don't see the need to go to the sand, but, the possibility of ending up there is real. I don't dive 1.6 anymore, and my target is always 1.4 or less, especially in currents.

The thing to remember on this wreck is that it is symetrical below 90'. Most everything you can see between 50fsw and 92fsw is just repeated deeper (with some exceptions). I plan my dives on the Grove to allow me a descent to the bottom if neccessary, but a target in the lower third of the wreck.

The helium reduces the narcosis, and the END at max depth is only 52fsw with 30/30.

The cost to fill an OMS Faber 98 cubic foot tank with 30/30 trimix is about $22.00 (well worth it in my mind on this kind of dive).

That all being said, I don't think his gas mix had anything to do with the accident.

 

[gpatton]

A couple of points for discussion:

1. I'm sorry that you were asked to remove your earlier posts, Vickie. .................

2. As to the nitrox discussion, I don't see any evidence from the accident report that nitrox played a role. ........................

3. I was wondering if he simply got separated from his buddy, exhausted his air at depth trying to rejoin him/her, then panicked from an OOA incident (and we can't rule out an arterial gas embolus from a possibly rapid ascent.) This explanation seems consistent with his behavior at the mooring buoy, explaining the empty tank and BC, the rush to swim for the boat, and his failure to make himself positively buoyant at the surface (dropping weights, removing/inflating BC, etc.) Panic is a scary thing, and it's been shown over and over to be a killer of divers. It's one of the few things that I'm really scared of underwater.

All of this is, of course, just speculation. I've been drawn to the case because the victim was only a year older than me, seems to have been an intelligent man and a trained, competent diver, was diving a site that I love to dive, and had an accident that cost him his life. A little too close to home...

Thanks for posting the accident report. I think that, for myself at least, analyzing the facts as they emerge and trying to make some sense of it all makes it a little easier to deal with the fact of this tragedy.

-Grier

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As Grier stated, "All of this is, of course, just speculation." We here search for the true circumstances and facts that lead to this tragic accident. Not to blame. So, that we can all dive safely and enjoy the sports that we all love...

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I lost a loved one at Molasses Reef about 30 years ago! I was out of town on a trip when it happened. The cause of death was officially “drowning”, which never satisfied all the why questions.

I don’t think there will be real answers as to why this accident happened as well. If the official cause of death is drowning, that will not answer all the why questions?? The question will be why did this diver drowned? I hope there will be more of comprehensive analysis of dive accidents in the future. Closure is important. I am still don’t have closure 30 years later. It still bothers me…

The question that keeps coming to the surface with me is the safety of Nitrox, if a diver hyperventilates? I just finished the Nitrox course and I am not convinced as to the all the general accepted safety aspects of Nitrox.

The first safety issue that I would question about Nitrox is the possible potential for disaster, if a diver starts Hyperventilating on Nitrox caused by whatever reason which could be numerous. During the Nitrox course work there was no warning or cautioning about how to avoid hyperventilation when using Nitrox or the potential results there of. Has this potential danger been overlooked by the dive industry??

I have researched Hyperventilation and found an interesting related condition that could possibly exacerbate the on set of Hyperventilation in a stressed diver. The condition is HYPOCAPNIA, it is a state in which the level of carbon dioxide in the blood is lower than normal. Hypocapnia can result from deep or rapid breathing, known as hyperventilation. Can Nitrox lead to this condition, which might bring on a situation of the diver Hyperventiling?

Most divers are aware Hyperventilation can lead to impairment and unconsciousness. In my opinion, Hyperventilation, while diving is a bad situation when breather air. How much worse is it when breathing Nitrox?

I don't think this accident was caused by excessive ppO2 of Nitrox at depth leading to impairment by Oxygen Toxicity. However, has there been due consideration of Hyperventilating Nitrox at any depth??

I would think that an accident caused by Hyperventilation would be almost impossible to detect during an autopsy. I don’t know if there is any latent chemical marks that are left behind. If anyone knows, please enlighten us.

Glenn
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Background Info
Hypocapnia
http://en.wikipedia.org/wiki/Hypocapnia
From Wikipedia, the free encyclopedia.
Hypocapnia, also sometimes known as acapnia, is a state in which the level of carbon dioxide in the blood is lower than normal. This can result from deep or rapid breathing, known as hyperventilation. Even when severe, hypocapnia is normally well tolerated.
However, hypocapnia causes cerebral vasoconstriction, leading to cerebral hypoxia and this can cause transient dizziness, visual disturbances, and anxiety. A low partial pressure of carbon dioxide in the blood also causes alkalosis (because CO2 is acidic in solution), leading to lowered plasma calcium ions and nerve and muscle excitability. This explains the other common symptoms - pins and needles, stiff muscles and tetany in the extremities, especially hands and feet.
Hypocapnia is sometimes induced in the treatment of certain medical emergencies, such as intracranial hypertension.


Hyperventilation
http://en.wikipedia.org/wiki/Hyperventilation
http://home.earthlink.net/~drbobshields/Hyperventilation.F.html

From Wikipedia, the free encyclopedia.
In medicine, hyperventilation, also known as tachypnea or hyperpnea, is the state of breathing faster or deeper than necessary, and thereby reducing the carbon dioxide concentration of the blood below normal. This causes various symptoms such as numbness or tingling in the hands, feet and lips, lightheadedness, dizziness headache, chest pain and sometimes fainting.
Causes
Stress or anxiety commonly cause hyperventilation; this is known as hyperventilation syndrome. Hyperventilation can be brought about voluntarily, by taking excessive deep breaths. It can also result from inflating numerous party balloons by mouth. Hyperventilation also occurs as a consequence of various lung diseases, head injury or stroke, or when the body lacks oxygen (hypoxia), for instance in high altitude or as a result of anaemia. Lastly, in the case of metabolic acidosis, the body uses hyperventilation to counter the increased acidity of the blood.

http://www.medterms.com/script/main/art.asp?articlekey=3853
Hyperventilation: Overbreathing. This can cause dizziness, lightheadedness, weakness, shortness of breath, a sense of unsteadiness, muscle spasms in the hands and feet, and tingling around the mouth and fingertips. All of these symptoms are the result of abnormally low levels of carbon dioxide in the blood caused by overbreathing.
Hyperventilation is often due to anxiety or panic.

 

[Scott101]

"Can Nitrox lead to this condition, which might bring on a situation of the diver Hyperventiling? "

I am no expert by any means but I would think that no, Nitrox would not lead a stressed diver to hyperventilate. Nitrox only reduces the amount of N2 that you breathe, it doesn't increase the respiration (or consumption) of 02 nor does it effect the exchange rate of CO2 : 02. If this was the case, being put on 100% O2 effectively rob the blood of all CO2.

It's been awhile since I took physiology and I may be way off on this but I don't think I am.

 

[mempilot]

CO2 can build up for a number of reasons:

1. CO2 in the mix
2. deadspace in the breathing apparatus
3. shallow breathing (not eliminating CO2 adequately)
4. skip breathing (not eliminating CO2 in a timely manner)
5. rapid breathing (not allowing for the transfer of O2 and CO2 adequately)

Excess CO2 increases blood flow to the brain, which can elevate succeptability to O2 convulsions through an increased dose of O2 to the brain.

If a diver is stressed and is rapidly breathing while under exertion, it will cause a CO2 buildup. If they are breathing an elevated PO2, it can cause convulsions and subsequently, drowning. An overweighted diver who has either passed out from CO2 or O2 convulsions could easily sink back beneath the surface.

If he was breathing ean30, the mix is about .3 PO2 at the surface. Even an elevated dose due to CO2 retention probably wouldn't cause convulsions.

Higher mixes such as 100% and 80/20 often used in decompression could theoretically induce this problem during stress and exertion at or near the surface.

For this diver, a more likely cause would not be from the nitrox, but from a CO2 blackout from rapid breathing under stress and exertion. He may have had muscle cramps as well, limiting his ability to stay mobile while overweighted. If his tank was empty and he couldn't kick while experiencing a CO2 buildup, the results could be disastrous.

All speculation.

 

[pt40fathoms]

The question that keeps coming to the surface with me is the safety of Nitrox, if a diver hyperventilates?

I have researched Hyperventilation and found an interesting related condition that could possibly exacerbate the on set of Hyperventilation in a stressed diver. The condition is HYPOCAPNIA, it is a state in which the level of carbon dioxide in the blood is lower than normal. Hypocapnia can result from deep or rapid breathing, known as hyperventilation. Can Nitrox lead to this condition, which might bring on a situation of the diver Hyperventiling? ]

Answer...No! Do a little more research please! The dangers with hypocapnia caused by hyperventilation is directly associated with free diving, not open circuit scuba, and is called shallow water blackout.

Most divers are aware Hyperventilation can lead to impairment and unconsciousness. In my opinion, Hyperventilation, while diving is a bad situation when breather air. How much worse is it when breathing Nitrox?

Where are you getting this information? I think you have made some leaps of logic here.

I don't think this accident was caused by excessive ppO2 of Nitrox at depth leading to impairment by Oxygen Toxicity. However, has there been due consideration of Hyperventilating Nitrox at any depth??

I would think that an accident caused by Hyperventilation would be almost impossible to detect during an autopsy. I don’t know if there is any latent chemical marks that are left behind. If anyone knows, please enlighten us.

The results hyperventilation while using open circuit scuba, would be a high consumption rate of gas, and associated temporary physical symptoms. Nitrox does not cause a diver to hyperventilate, not does it exacerbate it. You are unfortunately making a very big leap of logic with limited knowledge of only a few facts. There have been numerous studies of the effects of enriched air on divers, none of what you have said is even on the radar as a consideration. The diver who died surfaced for a period of time and is said to have responded verbally to the dive boat crew, so shallow water blackout can be ruled out, as would an embolism. He had an empty tank, an empty BCD and all his weights on when found. Those are the only facts we know so far. We will never know his state of mind, or why certain decisions were made or actions taken or not taken by the diver that lead to his death. We can only gather the facts, such as they are, and reinforce a basic open water lesson to drop your weights if in trouble. This is as far as we can go in assessing possible courses of action that may have changed the outcome. The gas he was using had no bearing at all.

 

[pilot fish]

CO2 can build up for a number of reasons:

1. CO2 in the mix
2. deadspace in the breathing apparatus
3. shallow breathing (not eliminating CO2 adequately)
4. skip breathing (not eliminating CO2 in a timely manner)
5. rapid breathing (not allowing for the transfer of O2 and CO2 adequately)

Excess CO2 increases blood flow to the brain, which can elevate succeptability to O2 convulsions through an increased dose of O2 to the brain.

If a diver is stressed and is rapidly breathing while under exertion, it will cause a CO2 buildup. If they are breathing an elevated PO2, it can cause convulsions and subsequently, drowning. An overweighted diver who has either passed out from CO2 or O2 convulsions could easily sink back beneath the surface.

If he was breathing ean30, the mix is about .3 PO2 at the surface. Even an elevated dose due to CO2 retention probably wouldn't cause convulsions.

Higher mixes such as 100% and 80/20 often used in decompression could theoretically induce this problem during stress and exertion at or near the surface.

For this diver, a more likely cause would not be from the nitrox, but from a CO2 blackout from rapid breathing under stress and exertion. He may have had muscle cramps as well, limiting his ability to stay mobile while overweighted. If his tank was empty and he couldn't kick while experiencing a CO2 buildup, the results could be disastrous.

All speculation.

Are there any reports of him bolting to the surface? Is it possible he ran out of air at depth, had a gear malfunction, etc, and bolted to the surface causing an embolism?