Spiegel Incident

[TSandM]

If his SAC rate was .7231856 and he was using a 100 cf tank, filled to exactly 89.4138 cubic ft does not seem to change the event, or any lesson to be learned. . . The discussion as to what tank should be used to make a 110 ft dive (or whatever depth one wants to fill in) would seem to be somewhat relevant in the big picture, but not to the S Grove, as when dawn breaks tomorrow, there will still be people (weather permiting) heading out to dive it with AL80's

I really feel the need to differ with this. It is clear from the descriptions of the site, that it can be dived at different depths. If one knows ones SAC rate, and briefly compares that to the 77 cubic feet of gas one is carrying, one gains really valuable information about how much bottom time can be expected at the varying levels where the dive can be done. An understanding of the concept of rock bottom reserves also would impact the dive planning.

Nothing is going to change the fact that this happened. But, especially given that divers on the SG don't appear to have much choice about what they can use for a starting gas volume, education MAY help people make a better decision about what DIVE they do using that gas. Although an uncontrolled ascent clearly appears to have been the proximate cause of this injury, it was initiated by a diver who was anxious about being low on gas; had he planned carefully, that anxiety might never have occurred, and the ascent might have remained under control.

 

[vladimir]

This thread has quickly gone to crap. We don't even know that Matt was at 135' nor his SAC rate and yet we have people posting tables and gas compsumption data...... But I can't say that I'm shocked......

I wish the moderators would make an explicit statement in the stickies on how to treat speculation here, so we don't have to have this discussion every time a new accident thread is opened. Maybe something like:

(7) If your post is your hypothesis, theory, or a "possible scenario," identify it as such.

That seems like an explicit okay of the hypotheses, theories, and possible scenarios that seem to arouse so much disdain in here. Perhaps it would help if everybody used [speculation][/speculation] tags where applicable.

 

[lamont]

[plausible]
Plausible scenario for how a recreational diver gets explosively bent on an Al80:

120 feet for 27 minutes with a 0.60 cuft/min SAC will use 77 cu ft of gas.

A 40 second ascent from there produces 120% GF oversaturation in the 5 min compartment and 150% GF oversaturation in the 12.5 min compartment.

Adding just a 5 min @ 15 feet stop caps the oversaturation on the ascent phase to 100% in the 12.5 min compartment, and on surfacing, 126% in the 18.5 min compartment, with 94% in the critical 5 min compartment.

That probably makes the difference between a dive that you walk away from and one that you might not. The 15 foot stop is within buhlmann limits and lets your lungs clean up a lot of bubbles, and reduces the surfacing gradient and pushes it to somewhat slower compartments.

10 mins @ 15 feet results in only 34% GF oversaturation in the fastest compartment (decompresses the blood) and 108% GF in the most saturated (18.5 minute) compartment, and is close to the buhlmann-style deco for this dive. You might feel like crap after that dive, but type 2 DCS wouldn't be likely.

The 5 minute stop uses 280 psi of gas with this diver, the 10 minute stop obviously uses 560 psi of gas.

The moral of the story is that 5 min @ 15 feet does a lot to decompress you, and takes very little gas in an Al80.
[/plausible]

 

[openmindOW]

Last I heard, there was not many rental or charter boat tanks larger than 80 cf on Key Largo. They seem to like the standardization of the 80s a lot there, and many Ops think nothing to taking OW divers on air to the SG.

I think you are correct, Don. I was recently diving in KL and on the SG. 80s are a common rental tank used in KL, although I know of a dive operation there that rents doubles as well.

I know of dive operatiers in KL that take divers to the SG on air. Really, there's nothing wrong with that. The top of the SG is APPROXIMATELY 80' of depth.

Personally, I like KL diving because operators tend to not baby-sit divers. Divers are expected to plan their own dives and to be back on the boat by a given time.

 

[openmindOW]

The discussion as to what tank should be used to make a 110 ft dive (or whatever depth one wants to fill in) would seem to be somewhat relevant in the big picture, but not to the S Grove, as when dawn breaks tomorrow, there will still be people (weather permiting) heading out to dive it with AL80's

Absolutely correct. That is what goes on at the SG every diving day.

 

[openmindOW]

. . . given that divers on the SG don't appear to have much choice about what they can use for a starting gas volume, education MAY help people make a better decision about what DIVE they do using that gas.

Amen. Better training would help.

 

[Puffer Fish]

I really feel the need to differ with this. It is clear from the descriptions of the site, that it can be dived at different depths. If one knows ones SAC rate, and briefly compares that to the 77 cubic feet of gas one is carrying, one gains really valuable information about how much bottom time can be expected at the varying levels where the dive can be done. An understanding of the concept of rock bottom reserves also would impact the dive planning.

Nothing is going to change the fact that this happened. But, especially given that divers on the SG don't appear to have much choice about what they can use for a starting gas volume, education MAY help people make a better decision about what DIVE they do using that gas. Although an uncontrolled ascent clearly appears to have been the proximate cause of this injury, it was initiated by a diver who was anxious about being low on gas; had he planned carefully, that anxiety might never have occurred, and the ascent might have remained under control.

Don't disagree with you at all... I would not let anyone do that dive without some understand of gas management and having a plan before they jumped in the water, was just stating reality.......

While I was on the Bibb that day, two days earlier I was the S grove...and did a nice relaxed 46 minute total dive time, with a maximum depth of 105 ft... using 31% nitrox. In addition to having a pony with me, I surfaced with just under 1,000 psi, but that was the plan before entering the water.

 

[riftvalley84]

I am surprised more information about the incident has not become public by now. Usually other divers on the same charter, locals, etc. chime in soon after such an event.

This information was posted on his CarePage site that someone in this thread posted a link to earlier. I hope his recovery goes better than they are currently expecting.....

There was a huge meeting today which included all the Doctors, Nurses, Physical Therapist's, Occupational Therapist's, Hospital Psychologists, Social Workers, etc...everyone involved --discussing Matthew's case. Matthew will remain in this Rehab Center until March 8th. At that time the case will be reevaluated, and a decision made. The first three months are critical for his recovery, and a final assessment will be made at 12 months. At the current time (24 days), all Doctors involved have concurred and given Matthew a "medical diagnosis" of "Quadraplegic". This is due to the location on the injury involving the Cervical Vertebrate (between C6 and C8),and the lack of full use in his arms. His right arm is 80%, and his left arm is somewhat less, including a curled small finger, and numbness, and lack of feeling on the underside of his arm. Matthew's response to today's news was, "Well....I can't control what happened to me, but only how I respond to it."

 

[skdevlieger]

go to carepages.com/matthewdevlieger for the daily update. Matthew is a 21 year old Junior at Calvin College, from Grand Rapids,Michigan, who was scuba diving at Spiegel Grove in Key Largo, Florida, on December 28,2010. He ascended too quickly, and the nitrogen bubbles, which formed in his bloodstream, expanded, and cut off the blood supply to his spinal cord. This caused a massive Tsunami style stroke to his spinal cord, leaving him a quadraplegic as of January 20,2010. He is at the University of Miami Jackson Rehab center in Miami Florida for the next few months. Please pray for his recovery. Also,if anyone knows of any other divers who have had a similar story, and their recovery story, please go to carepages.com/matthewdevlieger and post it.

 

[skdevlieger]

He was not diving with nitrox. Just a regular tank fill.