An important point to consider is that the computers are set to set to 50 meters (164') exactly, but for RD2.0 I had to round up to next depth (170') on the table - which put RD at a disadvantage from the start. A profile like this would allow for RD averaging to the 48 meter table, which I am including in an expanded data set for comparison below.
Notice that my 48m RD2.0 profile (which is the one I would actually dive for this dive), only slows down just a bit for the gas switch stops, but can closely mimic Buhlmann profiles.
@victorzamora - it is the low gf that determines deep stops - not the high gf. Doesn't it concern you that 30/70 and 30/80 develop such different deep stops? It does me. It just shows me even more that it's all just theory. Even this latest study doesn't prove anything conclusively. You still have to choose your flavor of risk.
I think you may be missing the point. There are other advantages to RD besides believing in O2 windows or less over pressurization of fast tissues. RD keeps the team together - even during deco. I can't count how many times we've planned deco dives based on tables, and then when we got to the stops, the team split apart to follow their individual computers! Here is a great explanation by Dan:
Bottom line comes down to two things: 1. how much overpressure gradient are you willing accept for fast tissues, and 2. do you believe in the oxygen window. If you don't believe in the O2 window, and are willing to approach m-values (also theoretical) for fast tissues, then don't slow down until you get shallow.
believe what you want to believe.
enjoy,
Notice that my 48m RD2.0 profile (which is the one I would actually dive for this dive), only slows down just a bit for the gas switch stops, but can closely mimic Buhlmann profiles.
@victorzamora - it is the low gf that determines deep stops - not the high gf. Doesn't it concern you that 30/70 and 30/80 develop such different deep stops? It does me. It just shows me even more that it's all just theory. Even this latest study doesn't prove anything conclusively. You still have to choose your flavor of risk.
I think you may be missing the point. There are other advantages to RD besides believing in O2 windows or less over pressurization of fast tissues. RD keeps the team together - even during deco. I can't count how many times we've planned deco dives based on tables, and then when we got to the stops, the team split apart to follow their individual computers! Here is a great explanation by Dan:
Hello Tassi,
Thanks for the question. My personal view on it may not benefit the next diver, and it stands on my own accord entirely, so please take this just as one personal view.
Ratio Deco builds on standard gasses.
If one doesn't know what specific depth one is going to, I can use the that framework to prepare for a sequence of dives in the exploration domain, which would in some cases make an "optimal" gas and deco approach difficult (how do you mix the "perfect" gas for a dive that you don't know the depth of yet?), but rather build the dives on gas logistics, Ratio Deco and maximal operative depth, in a manner proactive rather than reactive in-water.
Further, it works well in a mixed team, across rebreathers/open cirquit systems as well as any number of personnel.
Personally, if I travel to a different country or continent, and meet a person I want to go diving with, and we don't speak any of the same languages, which happens, that's samlessly facilitated as well, in terms of decompression. There's no way to quantify such utility with doppler technology.
To be sure, Ratio Deco doesn't numerically factor in, say, fatigue, hydration, exertion, temperature, nor do the alternatives, to my knowledge. But it does certainly build a familiarity and readiness towards adaptation, which may or may not be helpful in some circumstances.
In the classroom, I see the educational benefits in progressive addition of further "layers" when using the Ratio Deco-methodology as quite significant. As an open water diver, one learns the base upon which technical dives build it's approach, and so, as a diver, I attain recognition across levels of education and familiarity in application to diving.
Viewed separately as a training tool, I find it beneficial to add the deco sphere of Ratio Deco to the awareness of a diver, that they naturally learn to manage not just the dive as it may unfold, but at the same time consider and evaluate deco versus gas logistics and make choices based upon those factors.
These benefits of course wouldn't be quantified in a comparative study, which is why I think they're benefits that transcend how two deco plans for one dive work, compared to oneanother.
There's of course the cost factor, which naturally shouldn't dictate our choices, but in fairness, my 330 has cost me less than $1 per month in use towards computer and software, training cost aside (I omit that cost as I assume it would be a factor near enough constant across solutions/agencies, and even if it isn't, Ratio Deco surely wouldn't be the only factor differing across them).
Further, I don't depend on external hardware or software, and I don't risk taking on a habit of "outsourcing" my thinking.
These factors may not apply similarly or be weighed equally by all, and it's fair enough to point that out.
I am merely explaining examples of what I mean by benefits that transcend comparison of an "optimal" deco or gas for one dive versus a "standard" deco or gas for that same dive, specifically.
I hope my expansion brings clarity to my statement quoted, if not, I will be happy to take any questions you might have.
Best Regards,
Dan
Bottom line comes down to two things: 1. how much overpressure gradient are you willing accept for fast tissues, and 2. do you believe in the oxygen window. If you don't believe in the O2 window, and are willing to approach m-values (also theoretical) for fast tissues, then don't slow down until you get shallow.
believe what you want to believe.
enjoy,
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