Spiegel Incident

[Reg Braithwaite]

normally?

" So we're going to drop down to 185. Normally no one runs out of air"

Interesting way to plan a dive

As discussed elsewhere on SB...

 

[Kevrumbo]

[Spiegel Grove] for 15min bottom time at 140'; SAC rate 0.5cf/min; Air backgas; Ratio Deco 1:1; no wreck penetration/external tour only . . .:

Dpth'/Time(min):
140 15
130 0.3
120 0.3
110 0.3
100 0.5 [75% Deep Stop]
90 0.5
80 1.0
70 2.0 [Eanx 50 switch]
60 1.0
50 1.0
40 1.0
30 2.0
20 3.0
10 3.0
-> 3.0 surface

Total Time: 34min
Tanks used: Double AL80's plus AL40 deco bottle of eanx50
Eanx 50 needed: 16cf
Backgas needed for deco (i.e. loss of Eanx50 bottle): 77cf

No wonder [if only on a single AL80 cylinder] they ran low on gas. . .

 

[Reg Braithwaite]

[Spiegel Grove] for 15min bottom time at 140'; SAC rate 0.5cf/min; Air backgas; Ratio Deco 1:1; no wreck penetration/external tour only . . .:

Dpth'/Time(min):
140 15
130 0.3
120 0.3
110 0.3
100 0.5 [75% Deep Stop]
90 0.5
80 1.0
70 2.0 [Eanx 50 switch]
60 1.0
50 1.0
40 1.0
30 2.0
20 3.0
10 3.0
-> 3.0 surface

Total Time: 34min
Tanks used: Double AL80's plus AL40 deco bottle of eanx50
Eanx 50 needed: 16cf
Backgas needed for deco (i.e. loss of Eanx50 bottle): 77cf

No wonder [if only on a single AL80 cylinder] they ran low on gas. . .

Well, I don't think they were planning to ascend at 10 feet per minute or spend eight minutes on shallow stops. Do you want to try another run, this one assuming an ascent at 30 feet per minute and a five minute stop at 15'? It may not be to your taste, but you can at least get an idea of what they might have had in mind...

 

[Kevrumbo]

Okay then, on single AL80 . . .it basically becomes a "touch" or "bounce" dive to 140' for no more than 5min to 7min max bottom time.

(And I have no idea what they could've had in mind. . .)

 

[Puffer Fish]

An EAN50 deco bottle instead of EAN100? Odd to say the least...

Not really, I was using EAN50 on my dive about 1/2 of a mile from the S Grove that day.

There is good reason to use both...but if one only has one, I would choose EAN50.

The issue of using al 80's has a lot to do with limiting the dive time. If they used larger tanks, people would be getting into more deco issues than they do now...so in concept, using time limited tanks (if one pays attention to how much gas they have) is safer.

If someone was silly enough to go to the sand, then they would have a very short dive, or run out of air.

I don't know of any dive ops there that would allow a deco dive, with the standard tourest divers, so one should be safe in assuming that this was to be a simple, gas limited deep dive. The mild current that day might have allowed for slightly longer dives.

Looking at my first dive, I used 57 cubic ft with a max depth of 133ft and 16 minutes of actual bottom time...with a total dive time of 30 minutes. So it would be possible to do that with an 80, with gas to spare.

During our surface interval, we were looking at all the boats moored on the Grove, and they all appeared to be from the shops in the area...we had a small conversation about who each boat was.


Given the slow absorption of gas into and out of the spinal cord... a rapid accent DCS hit should not be a surprise (sad, but not surprising)

 

[Puffer Fish]

Okay then, on single AL80 . . .it basically becomes a "touch" or "bounce" dive to 140' for no more than 5min to 7min max bottom time.

(And I have no idea what they could've had in mind. . .)

The sand the boat is sitting on is around 130...normally, most divers are not below 105 or so and it is possible to do the dive and not get below 85 ft....

If one went to the sand, they would be seeing... well sand and a huge boat sitting on the sand.

 

[Scott L]

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.

 

[mrfixitchapman]

The sand the boat is sitting on is around 130...normally, most divers are not below 105 or so and it is possible to do the dive and not get below 85 ft....

If one went to the sand, they would be seeing... well sand and a huge boat sitting on the sand.

I'll have to admit, though, that it IS a very large boat sitting on the sand.

DC

 

[Puffer Fish]

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......

As you know, thousands of people make that dive every year. Almost all come back ok (using an AL 80).

Having a spinal dcs hit means it was a real dcs event (a lot of others could be PFO issues).. so we know:

1. He went down, absorbed gas.

2. Surfaced faster than that gas could get back out.

Important lesson there...

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.

It would be nice to know some of the details as to the "why", but given how protective the keys are about dive accidents and most of the information we have comes from home town papers, that care about the person and not the details, I would be very surprised if we every get more info.

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

 

[ianr33]

It would be nice to know some of the details as to the "why"

The details seem pretty clear to me: Diving beyond training/experience.

I hope he recovers.