Multiple 25 foot drills in a row???

[Superlyte27]

Saw-tooth profiles 0-25, 0-25, 0-25 etc is not a good idea. Your dive education tells you that. You are working in the zone where pressure doubles (1ata-2ata)!!! Yes it might work for some divers, but this is not good advise. I really don't care how many times others have done it without issue and I surely will not take any advise from someone (instructor, educator, mentor, leadership role) that does not know that nitrogen also gets absorbed in to bone.



Why don't the OP contact DAN and relay the response back?

How far back did you have to dig for that one? I guess given enough time and depth and exposure, nitrogen is absorbed everywhere, but if you'll read the entire posts from that thread, the diver was talking about very limited, very recreational profiles.

---------- Post added August 8th, 2013 at 07:49 PM ----------

Since when does bone not absorb nitrogen? Citation please?

I don't remember the exact post or thread, but my point was -iirc- that nitrogen is absorbed in fat FIRST. But, by all means, ask DAN.

 

[mopardiver]

Thanks everybody, I think I do have enough feedback to make my decision. I’m going to do it right off the bat after getting wet, suck on nitrox for extra safety, and maybe do it five or six times. I’ll also do the drill one final time at the end of my dive. I’ll probably do it from 28’ because there is a pretty strong thermocline at 25’ and I can use the drastic temp change to see if I can actually deploy it without rising three feet without looking at a depth gauge.

 

[Superlyte27]

A quick search online pretty much states my point that Nitrogen absorbs very slowly into bones, teeth, skull, etc. For the purposes of that thread, I'm going to stick with my statement that DCS is a non-issue due to her surgery.

 

[muddiver]

The new US Navy Diving Manual has a shallow water table. You can download it online and use that to figure your nitrogen loading. I would post a link if I wasn't on my iPhone. The Navy Manual is also available for most smart phones as well.

 

[Superlyte27]

Since when does bone not absorb nitrogen? Citation please?

And I don't have a citation, but was told by the guy who does most of the diving physicals for the GoM that DCS involves soft tissue not Skull, Bone, Teeth, etc. I think his name was Dr. Borgious or something like that in Louisanna.

---------- Post added August 8th, 2013 at 08:03 PM ----------



Okay, upon further research, I can find reports where Nitrogen Bubbles were found in bone marrow. Oh well, live and learn.
I don't need to know how the engine on my car works to understand what the gas pedal does.

 

[mopardiver]

Bone Bends…I hope that don’t regret not using V-Planner, slinging a stage and doing safety stops while sucking on O2 after each time! I hear there are fanged fish with dangly lures and built in lights at 25 feet in this rock quarry.

Sorry, I have a smart ass side to me if you can’t tell!

Thanks everybody, I have enough information, I will assume the risk of the drill, and now ten posts after posting my first question to this forum!!!

 

[PfcAJ]

If you're going to try and teach people to be mechanics you do.

Its not a matter of what absorbs the inert gas 'first', as gas absorption is across all tissues simultaneously. "Blood" might be fastest, but "muscle" is absorbing inert gas at he same time, just at a slower rate. Same goes for "bone", its just hypothesized to on and off gas at a slower rate than the rest.

A little research on dysbaric osteonecrosis yields some interesting info.

 

[Akimbo]

The new US Navy Diving Manual has a shallow water table. You can download it online and use that to figure your nitrogen loading. I would post a link if I wasn't on my iPhone. The Navy Manual is also available for most smart phones as well.

Courtesy of Scubaboard: US Navy Diving Manual

 

[muddiver]

Good job Akimbo, only I checked and the table ALSO only goes to 30 feet. Aaaarrrrggg

 

[Superlyte27]

If you're going to try and teach people to be mechanics you do.

Its not a matter of what absorbs the inert gas 'first', as gas absorption is across all tissues simultaneously. "Blood" might be fastest, but "muscle" is absorbing inert gas at he same time, just at a slower rate. Same goes for "bone", its just hypothesized to on and off gas at a slower rate than the rest.

A little research on dysbaric osteonecrosis yields some interesting info.

I get your point, but get mine...
Do we really need to know the intracacies of Type 1 or Type 2 DCS? The treatment is the same as far as we are concerned. Our job is to get to a doctor so he can get us in a chamber. Sure, the ride will probably be different. Do we really need to know if we got bent because the nitrogen is in our bones or our fat or our spinal cord or our.... NO, because we are bent. We're not doctors. We only need to recognize that we ARE bent, not to what degree because we're not the one treating it. So, nitrogen in bone, nitrogen in muscle, nitrogen in knees, legs, arms, brain, it doesn't matter.... guess what, the course of action is the same.... Get to a friggin doctor. Does ANYTHING in any of the books we teach change even a little bit if the DCS is in a bone versus an arm? Nope. Move on. There's nothing to see here.

Hey, guess what. If you get bent, regardless of where or how.... you're going to the doctor. Your job is the same. And I don't need to know how blood moves through the arteries or how bone marrow is fed to know that.