Sawtooth Profiles

[1atm]

the last graph is in ft yes?

Last graph in the thread (PfcAJs) is in feet. Mine (on prev page) is in meters

 

[dmaziuk]

So is the conventional view that there is an increased risk of DCI from a sawtooth profile incorrect or is it simply that the risk is slight in comparison with the other potential causative factors related to DCI?

I think the emerging/conventional view is that many of the bubble people's assumptions turned out to be wrong, and that reverse/sawtooth profiles thing is likely among those.

 

[kensuf]

Okay, the first one I get. That shape, with some scaling applied to depth and time, could be the profile for countless cave dives- including the classic "hope for the best" period of hauling butt over the "shallow" section on the way back out.

What the heck is this one though? It looks less like any place I've seen, more like the electronics in your computer got fried and this is the plot of the noise it generates now!

My guess is Manatee. For the first 4000' you're either at 100' or 30'. Over and over and over.

 

[kotik]

My guess is Manatee. For the first 4000' you're either at 100' or 30'. Over and over and over.

Yessir, correct. I felt a little bad for not recognizing it as I've been through a fair bit of that personally. In my defense it was only once, and it's been a couple of years. The up & down made an impression at the time for sure, but it really stands out looking at the graph.

 

[rjack321]

Yessir, correct. I felt a little bad for not recognizing it as I've been through a fair bit of that personally. In my defense it was only once, and it's been a couple of years. The up & down made an impression at the time for sure, but it really stands out looking at the graph.

The faster your scooter and the longer your dive the squigglier it looks!

 

[kensuf]

Not as dramatic, but 100' of profile change on this one.

 

[JonG1]

Bit of a thread revival, but I listened to Steve Boagarrts on Sidemount pros and 1 of his potential explanations for his spate of hits, is repeated saw tooth profiles and latent damage from them over time, esp when in a scooter and not coming off the trigger for the ascent portion.

 

[KenGordon]

Bit of a thread revival, but I listened to Steve Boagarrts on Sidemount pros and 1 of his potential explanations for his spate of hits, is repeated saw tooth profiles and latent damage from them over time, esp when in a scooter and not coming off the trigger for the ascent portion.

The very famous French bloke, a proper deco scientist, was talking about this at EuroTec. See if you can find anything there. I think this is one of the things people like to ignore as Buhlmann doesn’t take account of it. Even if you ignore all that critical radius stuff and just consider simple squashing it seems to make sense.

 

[rjack321]

Bit of a thread revival, but I listened to Steve Boagarrts on Sidemount pros and 1 of his potential explanations for his spate of hits, is repeated saw tooth profiles and latent damage from them over time, esp when in a scooter and not coming off the trigger for the ascent portion.

That might be true, but he was also diving every day for years, and he's an N=1. Would a twice daily square profile for 30 years been better? Nobody knows.