Spiegel Incident

[iztok]

As I read the narrative, the two young men who ran low on air did so after spearfishing around the SG. This brings up a whole new world of possibilities w/r/t gas supply and deco status. How much did they burn because they were swimming hard? How much up-and-down, and at what depths? How different were their "while spearing" depth/time profiles?
While it is certainly easy to get into a serious deco hole on 119's in 130 ft of water, it's also quite reasonable to burn through 100+ CF well within the NDL while actively spearfishing.

I am not spearfishing expert but If depth where they were doing spearfishing is over 100ft (135 max recorded) how much game is there in shallower water to hunt? I would assume most of the game would be around the bottom. Am I wrong?

 

[Web Monkey]

Thank you for confirming what I thought, and posted previously on this thread.

Lots of posters assuming there was a huge DECO obligation that was skipped, when in fact there might not have been any DECO obligation whatsoever.

Too many unknown variables.

Not really.

vPlanner calls for deco on anything more than an 8 minute dive @130'.

A 8 minute dive @ 130' uses less than 40 Cu Ft of gas even with my cold-water-and-drysuit SAC rate of .75

It take quite a bit longer than that to use up a 119, so I'm guessing that the dive was quite a bit longer than 8 minutes.

Even with a SAC of 1.5 (really unlikely unless panicking), the dive would have been squarely in deco territory long before the gas was gone.

Terry

 

[idocsteve]

Even with a SAC of 1.5 (really unlikely unless panicking), the dive would have been squarely in deco territory long before the gas was gone.

Terry

Thanks Terry that's an excellent analysis.

Also reminds me that I have been away from the tables for far too long.

 

[Web Monkey]

Thanks Terry that's an excellent analysis.

Also reminds me that I have been away from the tables for far too long.

No problem. Math is Fun.

Using up almost all of a 119 @ 130' (my cold water SAC) takes 20 minutes, and requires 27 minutes of deco, which is quite a significant Nitrogen load.

If we use my warm water SAC rate of .5 (which I'm guessing is worse than most warm water divers) it becomes a 28 minute dive with 57 minutes of deco.

Blowing off almost an hour of deco makes DCS in the victim easily explainable, and I can only guess that his buddy is either extremely resistant to DCS, very lucky or did the dive significantly differently.

Terry

 

[iztok]

Thanks Terry that's an excellent analysis.

Also reminds me that I have been away from the tables for far too long.

That is funny. When I did the same thing with Suunto dive planner and SAC rate of 0.8 you blasted me. Go figure!

 

[iztok]

Not really.

vPlanner calls for deco on anything more than an 8 minute dive @130'.

A 8 minute dive @ 130' uses less than 40 Cu Ft of gas even with my cold-water-and-drysuit SAC rate of .75

It take quite a bit longer than that to use up a 119, so I'm guessing that the dive was quite a bit longer than 8 minutes.

Even with a SAC of 1.5 (really unlikely unless panicking), the dive would have been squarely in deco territory long before the gas was gone.

Terry

http://www.scubaboard.com/forums/accidents-incidents/320007-spiegel-incident-15.html#post4996456

With Suunto algorithm.

 

[idocsteve]

That is funny. When I did the same thing with Suunto dive planner and SAC rate of 0.8 you blasted me. Go figure!

Sorry about that, I do remember reading something about it in one of your posts, I guess Terry presented in a simpler way that was easier for me to understand especially since I tend to skim the longer more detailed posts especially if they've got lots of numbers in them...lol

 

[iztok]

Wow, I just used my Suunto dive planner using HP119 as a template and 0.8 SAC rate (high). If I try to simulate depth of 130ft and profile where one starts getting up at slightly under 500psi it gets about 27 minutes of bottom time.

Which puts one in quite big deco obligation (according to Suunto algorithm).

According to it one would have to have about 66min total time before surfacing (obviously one would run out of air before that).

If I change SAC to .7 I get 31 min bottom time and almost 80min total dive time. (And running out of air before hitting 10ft deco ceiling.)

Scary.

Sorry about that, I do remember reading something about it in one of your posts, I guess Terry presented in a simpler way that was easier for me to understand especially since I tend to skim the longer more detailed posts especially if they've got lots of numbers in them...lol

See above what I wrote way back Not that complex

 

[bsee65]

If Matthew's mom is still out there, I hope we can get some answers here. I think that these answers would remove a lot of the speculation and allow a much more accurate assessment of what caused the injury. Admittedly, we may have given her enough already to arrive at some answers and there's no reason she needs to give us all the specifics.

Information that would still be interesting for discussion:

1. How long were they on or around the bottom before dad left?
2. Was dad actively fishing as well, or just hanging and watching his sons play around?
3. What were dad's turn pressure and ascent profile?
4. What were the twins' pressure when dad turned?
5. How often were they checking their pressure levels?
6. How long after dad left did they remain before starting ascent?
7. If there were no gas issues, what was their original ascent plan?
8. While thay have made many dives together, had they been to the Spiegel Grove before?
9. How about other dives at this depth?
10. How many dives had they done since getting the 119s? Any other deep dives?

 

[idocsteve]

See above what I wrote way back Not that complex

Maybe it was late at night and I was tired.