Modern research/thoughts on Ascent Rates

[kensuf]

You mean the guys in their trucks on oxygen and eating handfuls of Motrin were not doing it for fun?

Dr. Kepper at the TCH chamber and several of us were on a first name basis.

 

[Superlyte27]

I think on any dive with a major deco obligation, mitigating the speed from 10’ to 1’ is prudent. E.g 1’/min for the last ten feet on a 6hr dive is relatively minor in the grand scheme of things. Add in some surface deco and general relaxation, and I’d assert that the margin of safety is improved. Caveat emptor, “major deco obligation” is a relative term.

I think that if you’re that close on being bent that the last 10 feet will save you, you’ve done things wrong long before you get to 10’.

 

[Wibble]

Empirical evidence…

I find that I get less tired after a dive if I set my last stop to 3m/10ft on the computers and ascend to 4.5m/15ft or thereabouts depending upon the sea conditions and also do a slowish ascent to the surface when deco has cleared,

Since doing this I don’t seem to be anywhere near as tired as I was before this strategy.

Not sure if there’s feel like that. But it works for me.

 

[kaylee_ann]

I think that if you’re that close on being bent that the last 10 feet will save you, you’ve done things wrong long before you get to 10’.

Uhhhh yeah. Agreed. Just for fun, I've ran stupid dive profiles on subsurface. One was a deco dive (60 ft, 85 mins) using GFs of 75/95. Gave me a 43 minute stop at 10 feet- the only deco stop in the plan. If I set the last stop at 20 feet, it's an 80 minute stop. Neither sound appealing to me. Having the majority of your deco being at a much shallower depth just doesn't seem like a good idea.

 

[grantctobin]

Uhhhh yeah. Agreed. Just for fun, I've ran stupid dive profiles on subsurface. One was a deco dive (60 ft, 85 mins) using GFs of 75/95. Gave me a 43 minute stop at 10 feet- the only deco stop in the plan. If I set the last stop at 20 feet, it's an 80 minute stop. Neither sound appealing to me. Having the majority of your deco being at a much shallower depth just doesn't seem like a good idea.

Can you refresh us on your dive experience? At very least, an articulation of why you picked such gradient factors and a demonstration of which gasses you’re using?

To help you understand why you’re off base, that aforementioned dive to 60’ for 85min has only a 1min 10’ stop on 32% on GF50/80, which would have cleared by the time most people ascended to it. Getting shallower quickly is effectively the research trend over the past ten years…

Had I just passed my open water last month as you have, I probably wouldn’t be posting decompression advice on the internet. Alas, that’s me. Congrats on having finished!

 

[kaylee_ann]

Can you refresh us on your dive experience? At very least, an articulation of why you picked such gradient factors and a demonstration of which gasses you’re using?

To help you understand why you’re off base, that aforementioned dive to 60’ for 85min has only a 1min 10’ stop on 32% on GF50/80, which would have cleared by the time most people ascended to it. Getting shallower quickly is effectively the research trend over the past ten years…

Had I just passed my open water last month as you have, I probably wouldn’t be posting decompression advice on the internet. Alas, that’s me. Congrats on having finished!

I wasn't posting advice? all I said was for fun I ran GFs on subsurface to see what deco would come up.
ETA I didnt put nitrox in, it was just air

 

[inquis]

Gave me a 43 minute stop at 10 feet

I'm afraid I can't duplicate your results. I get only 17 mins deco at 10 ft on air.

 

[kaylee_ann]

I'm afraid I can't duplicate your results. I get only 17 mins deco at 10 ft on air.

didn't think of adding a deco gas or anything, was just on air rather than nitrox (dumb but so was the whole dive plan lol)

 

[inquis]

@kaylee_ann - You might double-check the options you've specified in the planner. I've checked Subsurface and Techdeco which pretty much agree. My configuration shown below if it's helpful.

I suspect you may have another dive just prior in the main list of dives, making this one a repetitive dive. That's especially easy to do when playing with various scenarios.

 

[kaylee_ann]

@kaylee_ann - You might double-check the options you've specified in the planner. I've checked Subsurface and Techdeco which pretty much agree. My configuration shown below if it's helpful.

I suspect you may have another dive just prior in the main list of dives, making this one a repetitive dive. That's especially easy to do when playing with various scenarios.

View attachment 738020

ah- that's it- repetitive dives. thanks!