Record Depth

[padiscubapro]

Dave Shaw using a 15.5 (with the Mark 16 Center Section) and Hammerhead Electronics, just set a world record of 270 Meters (rebreather/cave). His mix was 4% oxygen / 80% Helium.

While down in this cave, he decided to run a line out to explore some of the bottom, and found the body of a dead diver who had attempted to set an Open Circuit record in this very same cave 10 years ago.

Dave reported the HH performed "flawlessly", and followed the deco specified by the HH. He also had 2 vr3s as backup, one of which totally flooded.

[caveseeker7]

Who was that who questioned the MK 15.5's capabilities a little while ago ... ?

Dave Shaw using a 15.5 (with the Mark 16 Center Section) and Hammerhead Electronics, just set a world record of 270 Meters (rebreather/cave). His mix was 4% oxygen / 80% Helium.

While down in this cave, he decided to run a line out to explore some of the bottom, and found the body of a dead diver who had attempted to set an Open Circuit record in this very same cave 10 years ago.

Thanks, Joe.
Do you know more about the dive profile (ie bootom time), which cave where, that sort of thing?

Who was the fatality?

Thanks
Stefan

[opiniongirl]

Holy crap!!!!!

I dunno how I'd feel about having such a ominous greeting....now us gals need to catch up!

[tnt2020]

Stefan,

You can see the article on Divernet.com/new/stories/record011104.shtml
Opinion girl you'll be happy to know a Venra van Shaik set a record of 221m with the same dive group @ Boesmansgat Cave, South Africa.

Tnt

[Al Mialkovsky]

I'm glad numbers don't mean that much to me.

Especially since the checking account is pretty much empty

[rjens]

Figured I'd get the inside scoop here, the effort is referenced on page 28 of todays Sports Illustratted... under signs of the apocalypse.

[caveseeker7]

You can see the article on Divernet

Thanks for the link to the story.
Nice to see the MK15.5 didn't implode.
Would be nice not to get bend, though ...

While record dives for records' sake never did much for me,
on this one at least they discovered the remains.

[teksimple]

"The [DCS] symptoms may well have been provoked by carrying out work at excessive depth."

Since the algorithm's on both the VR-3 and HH are both modified Haldanean, I propose that using a dual-phase model such as RGBM (eg more deep stops, less shallow stops) may have helped reduce the chance of DCS at that depth. Any comments on why he did not use Abyss or Vplanner tables? Would David Shaw venture to post his deco schedule or a trace from his HH?

[padiscubapro]

"The [DCS] symptoms may well have been provoked by carrying out work at excessive depth."

Since the algorithm's on both the VR-3 and HH are both modified Haldanean, I propose that using a dual-phase model such as RGBM (eg more deep stops, less shallow stops) may have helped reduce the chance of DCS at that depth. Any comments on why he did not use Abyss or Vplanner tables? Would David Shaw venture to post his deco schedule or a trace from his HH?

The article failed to mention that the symptoms were started where he had his VR3 computers on his wrist.. Dave told Kevin he thought he might have had the computers on too tight and it felt like there may have been circulation restrictions..
The sysptoms may have cured on their own but he wasn't taking any chances..
RGBM wouldn't necessarily have given him an more deep stops... I run both models side by side ALL the time, so I can pretty much tell you with the right settings they track very closely and only deviate at the shallowest stops...

The VR3s were there as backup but the shape was determined by the HH and backup tables since the VR3 only does a limited number of deep stops before the "mandatory" stops.
On the deep stuff we ran in Indonesia, even with the extremely long decos the run times on the HH where just slightly longer compared to RGBM..
ALso the depth of the dive is beyond the calibration data of RGBM...
As depths go beyond 100m RGBM and VPM begin to diverge. This is becuase of the way they deal with skin tensions and the inteaction between boundaries and some other issues.. RGBM deals with these issues up to 180m, VPM hits its "wall" much shallower.. The fact is under the pressures listed, fluids and interaction with the varoius boundaries changes, and there is very little data to quantify it..

[padiscubapro]

"The [DCS] symptoms may well have been provoked by carrying out work at excessive depth."

Since the algorithm's on both the VR-3 and HH are both modified Haldanean, I propose that using a dual-phase model such as RGBM (eg more deep stops, less shallow stops) may have helped reduce the chance of DCS at that depth. Any comments on why he did not use Abyss or Vplanner tables? Would David Shaw venture to post his deco schedule or a trace from his HH?

I found out a bit more about the dive..

ALL the predive profiles were done with VPM, The 2 vr3s and nitek He were there strictly as timers..

in the divers words

"I was carrying two VR3’s and a Nitek He, but I was only going to be using them as bottom timers. The VR3 algorithm at this depth was not for me. The dive would have been far too long. The Nitek He could not cope with the fact I was diving a rebreather and would be bent in a flash, thus my decision to use VPM-B generated tables."


My guess is that he Had the HH on a very agressive GF to have it come close to VPM..

About the dcs here is a quote from the diver

"While resting I noted a dull ache in my left forearm. My Nitek He computer had been too tight around my wrist but I had not noticed at the time. It obviously had restricted the blood flow and now I was paying the consequences. The pain did not reduce with O2 therapy, or overnight so the next morning I elected to go to the Welkom chamber just in case. DAN decided it was best to undergo treatment in the chamber as a precaution. The pain went within two hours of starting the treatment."


About the performance of his equipment
"One VR3 had failed as I reached the bottom but the other soldiered on faithfully. I had tied off and was exploring, at a depth of 260m and descending. The unit was breathing well. The Hammerhead was keeping an accurate 1.3 PPO2 and I was relaxed and could almost not believe where I was."