Another Deco profile post.

[Serge Tao]

What's next? Increasing the oxygen percentage of your deco mix every 6 inches?

 

[Patoux01]

Well yes, it's called a rebreather.

 

[boulderjohn]

Just think it through with a thought experiment. Breaking stops into smaller time and depth segments (2seconds/6inches) means you can leave that stop sooner and ascend, because your ceiling no longer has to be 10ft above you but 6in. Your stop depth becomes 30ft when your ceiling becomes 29ft and stays that way until your ceiling reaches 19ft. If your stop depth changed at 29ft, you could deco at 29.5ft and then move up to 29ft when your ceiling moved up to 28.5ft.

If you had a stop resolution of 2 seconds and 6 inches, you'd be following the ascent curve closer than I would be at 1min/10ft. While I was still at 30ft for X minutes before ascending to 20ft, you'd be slowly ascending from 30ft to 20ft during that time.

I'm not saying it's better, and it's certainly not practical, but it would follow the GF-line closer than the standard 1min/10ft stop resolution.

It seems to me that we are in this case reigniting the more than a century old debate as to whether it is better to ascend in a series of stops or better to ascend slowly and continually. IIRC correctly, most people think the winner in that debate was a series of stops.

 

[Carl_F]

It seems to me that we are in this case reigniting the more than a century old debate as to whether it is better to ascend in a series of stops or better to ascend slowly and continually. IIRC correctly, most people think the winner in that debate was a series of stops.

"Better" can be relative. From a decompression efficiency, the continual ascent is "better". But "better" also can encompass diver ability and comfort and task loading. My personal ability is not conducive to continual ascent. And I have no desire to follow a continual ascent curve to that level of detail. It would be no fun. And the slightest bit of extra task loading would put me off the continual ascent curve. A huge PIA. So reasonable, step-wise, approximation of the curve (i.e., series of stops) works great for me and is "better" for me ... and for pretty much everyone else since that's what's taught and practiced from what I have seen. So the marketplace of ideas would conclude the series of stops is "better" overall.

 

[victorzamora]

It seems to me that we are in this case reigniting the more than a century old debate as to whether it is better to ascend in a series of stops or better to ascend slowly and continually. IIRC correctly, most people think the winner in that debate was a series of stops.

I actually wondered if there was some possible benefit to reducing the deco stress by maintaining the 10ft stop depths and then quickly reducing the pressure to another, 10ft shallower, depth....but it brings up a fair point:

My statement was simply meant to be explaining the "proof" that it would more accurately follow the theoretical curve to the surface and that it would be a "shallower" profile than 10ft stop increments.

I have no idea if it's actually better to do a smooth profile or a 10ft stop increment profile....but I know I'd struggle mightily with 2 second and 6 inch stop increments or a fully continuous curve.

 

[lermontov]

I actually wondered if there was some possible benefit to reducing the deco stress by maintaining the 10ft stop depths and then quickly reducing the pressure to another, 10ft shallower, depth....but it brings up a fair point:

My statement was simply meant to be explaining the "proof" that it would more accurately follow the theoretical curve to the surface and that it would be a "shallower" profile than 10ft stop increments.

I have no idea if it's actually better to do a smooth profile or a 10ft stop increment profile....but I know I'd struggle mightily with 2 second and 6 inch stop increments or a fully continuous curve.

I suppose you could get down to finer and finer points such as what tissues can withstand greater/lessor gradients at the expense of other tissues in regard to maximum off gassing and DCS risk