What's the current thinking on a reverse profile series for technical dives?

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I found the test subject:

biscuit_scuba.jpg


On a serious note... if I'm reading the abstract right, the experiment exceeded NDLs, with minimal SIs. That doesn't necessarily mean the Workshop findings were wrong
 


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I responded int the T2T forum to your question about my having any reverse profiles.

but FWIW ...Only one day did i had a reverse profile and it was due to a team member bailing out on the descent of a 200 foot dive. Dive 1 79 feet, Dive 2 214. In looking at my SW graph for the second dive it seems to be a pretty typical run with 23 minutes actual bottom time at 200+ and a total run time of 109, deco obligation was clear at 98 minutes.
 
George Irvine Lecture to BAUE 2002:
. . .The other way to get it [DCS] is to do a dive and then to do another quick dive down and come back up again. In other words, you've done a dive, you're getting out of the water and you are bubbling. Now you remember, "Oh, I left my oxygen bottle at 20ft." So you jump down with your mask on, grab the oxygen bottle and come right back up. Well, as you go down you compress the bubbles that are coming on the venous side enough to get by the heart, by the lungs. It just takes you a couple seconds to go down, a few seconds to go back up. Now they're expanding on the arterial side, and lodging in tissue. That's how we bent a bunch of support divers. That's how we found out about it. These guys didn't even do a dive, they'd be in a chamber. All he'd done is get oxygen bottles and be bent like a pretzel from that bouncing. Free diving after a dive, that's a classic one. . .

. . .You don't really have all this residual stuff during the surface interval. It doesn't really count. It doesn't really work that way. You can go back in the water and do it again as long as you're not bouncing. Remember what happens when you bounce. Once you get out of the water you're still cascading bubbles. You've started that process. You get back in the water, go down and come back up. When you relieve the pressure that process is going to resume and you're going to cause yourself problems. It's actually better to do deeper dives. But it's especially important if you're doing a second or third or whatever dive is that you stay down and ascend properly. You don't bounce it. You stay down and when you do come up that you do it meticulously. You really don't have to do a whole lot more deco on the second or third dive because you [should have] pretty much taken care of it by the first dive. And if you're in real good shape, you're going to be fairly clear after 30 minutes or so out of the water. And even if you're not in really good shape you're going to be, for the most part, clear. And you're not going to do any better if you're not in good shape. You get into that four-hour bit. If you go back in the water and recompress you're probably better off than if you're just sitting out of the water not diving. So you're not really going to have to, let's say, do twice as much or three times as much deco. I've done that for years, repeated dives and back-to-back dives, and it's never been an issue. But I also ascend real carefully. I think the bigger issue is tox. . .

http://www.frogkick.nl/files/george_irvine_lecture_to_baue.pdf
 
I'm not - I'm specifically asking for opinions and/or data on reverse profile technical dives. I provided the link & quote from the DAN workshop for discussion purposes
 
........ I'm specifically asking for opinions and/or data on reverse profile technical dives. .................

Great time to bring this up again. I'm very interested as I frequently do reverse profiles using my VR3. Not really a solid position, always wondering...

It has been a while since we've heard from Bruce Weinke. (http://www.scubaboard.com/forums/as...gbm-statistical-validation-2.html#post4735262)


YouTube - ‪Bruce Wienke interview of HelO2 and RGBM‬‏ -makes brief mention of it.

The "old stuff" 1999: http://www.si.edu/dive/pdfs/proceedings_reversediveprofiles.pdf

I wonder if the RGBM group have made any advances since the last report. The tail end of this clip (Eurotek 2010 - Discussing deco algorithms with Bruce Wienke - Rebreather World) leads me to believe that something new is due out fairly soon.
 
I found the test subject:

biscuit_scuba.jpg


On a serious note... if I'm reading the abstract right, the experiment exceeded NDLs, with minimal SIs. That doesn't necessarily mean the Workshop findings were wrong

You both have the same nose. :wink:

Good question though. I had only read the disclaimers on the old recreational warnings that have now been overturned, but in those they pretty much did not want to go further than the 130' envelope.

P.S.- What happened, nobody can afford goats anymore?
 
https://www.shearwater.com/products/peregrine/

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