Changes in my personal decompression regime

[Tortuga68]

It would seem to me that a shallow segment of a gas loading prior to a deep segment should have no bearing one way or another. Gas loading is gas loading, right?

So I would've thunk - but apparently not according to DAN; and while there has been discussion on recreational diving (within certain % parameters of reverse) it still seems to be a controversial topic, and I've not seen anything on reverse technical dives

 

[down4fun]

Kim, great information - thanks for posting!

Question: did you get an opportunity to chat with other divers diving similar profiles as you, besides out normal gang, and were they getting similar test results? If so, did most divers applying that 30/70 setting work for then too?

I've always used 25/85, so I'm not too far off on the deep stop setting, but the shallow stop setting is off a bit more, 70 vs. 85. That's why I asked the question about other divers results, because I understand the individual nature of these results, but I was wondering if you observed any patterns? I like the idea of being conservative in the water, but I do get tired of looking at Jeff and Tony on the longer hangs!

I know that one other diver who has participated in all three years of studies has made changes in his decompression schedules, he is not on a shearwater so it's not GF, but his changes resulted in longer shallow stops and he has had the same results...decrease in bubbling post dive. Bruce, from Shearwater will also tell you he is running 30/70 after some skin type symptoms (history not at innerspace) and has had none since the GF change. So it would appear that others are getting the same results when making changes. However, I will say there were some throwing 4-5's all week and felt no need to make any changes since they were symptom free. As for Tony and I, we agree the the cleaner we can get out of the water the better, symptoms or not.

Thanks for sharing, very interesting



Can you tell us the full depth/time dive schedule for your week?

day 1
dive 1 303
dive 2 306

day 2
dive 1 346
dive 2 84

day 3
dive 1 341
dive 2 213

day 4
dive 1 460

day 5
dive 1 79 (group member had to bailout during decent so i surfaced with them)
dive 2 214

day 6
dive 1 304

so the only reverse profile i see is the day that a group member had to bailout at the beginning of a 200 foot dive.

Just a tidbit here...His primary b/o had leaked unbeknownst to him so when he did b/o he had 1000#, he's big guy, and was a little anxious and blew thru that pretty quick. We were shallow enough that he signaled he was going to his deco gas. I watched with my b/o reg in hand. He gets the reg in his mouth, but no gas? He had an inline slide lock that had become occluded with shell debris during the swim out. He ended up on my reg until we got his gas fixed. Just something to think about for anyone using inline slide locks.

 

[down4fun]

Kim, great information - thanks for posting!

Question: did you get an opportunity to chat with other divers diving similar profiles as you, besides out normal gang, and were they getting similar test results? If so, did most divers applying that 30/70 setting work for then too?

I've always used 25/85, so I'm not too far off on the deep stop setting, but the shallow stop setting is off a bit more, 70 vs. 85. That's why I asked the question about other divers results, because I understand the individual nature of these results, but I was wondering if you observed any patterns? I like the idea of being conservative in the water, but I do get tired of looking at Jeff and Tony on the longer hangs!

This is a GREAT thread; Im so glad you posted this informative experience.



Why do you prefer the 25% GF for deep stops? Just curious as it seems it would make your first stop earlier and extend your deeper deco a bit.

Seems to me that everyone uses 20-35%. If you run the deco planner tables, there really isn't much difference in most normal tech diving schedules between even 25 and 35.

True and from what i have seen especially in the deeper dives, the deepest stops are cleared before you even get to them, so there seems to be little difference in the actual profile.