David Novo
Contributor
Is the GUE recreational ascent profile of 9m/min during the first half of the ascent and 3m/min thereafter an implementation of Buhlmann with GFs (with a 0 stop length at any stop, including the point where GFlo is reached)?
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It may be the other way round, since the safety stop came from research in the mid 1970s.Also don't forget about the 1m/min final bit.
Interesting question, makes me wonder where other agencies got the 3 min @ 5 meter safety stop from.
Yes, you are right. I guess I should have phrased it differently: by now, we know that doing a safety stop / really slow continues ascent works, it adds more conservatism to the profile. At the moment, there are several methods that achieve this ("traditional" safety stop / GUE style continues slow ascent). Does anybody know how these methods were developed / discovered?It may be the other way round, since the safety stop came from research in the mid 1970s.
Also don't forget about the 1m/min final bit.
Yes, you are right. I guess I should have phrased it differently: by now, we know that doing a safety stop / really slow continues ascent works, it adds more conservatism to the profile. At the moment, there are several methods that achieve this ("traditional" safety stop / GUE style continues slow ascent). Does anybody know how these methods were developed / discovered?
- developed into standards simply because people discovered it works?
- developed into standards because a certain model said so?
- developed into standards because there was a different theoretic benefit?
And follow up:
Are there significant differences between the various methods with regards to safety?
I guess we could include all the deep stop arguments in the discussion as well (like time in the water etc etc) but since this is about rec ascents I would be content with an answer like "this works in real life, corresponds with model X and the deviations from that model that are made are done because of reason Y"
I did fundies last year and there was no reference to 1m/min for the last 3m. Even "Beginning with the End in Mind" states that one minute from 3m to the surface is desirable but not mandatory.
I don't think the SOP is public domain, so I will not quote the entire thing, but if you did fundies you should be able to download the SOP 3.0 document. At the top, in the generic bit of the ascent profile, it mentions the last stop at 6 meter, with an ascent of 1 meter / minute to the surface. 2 lines after that is goes into the recreational specifics: last stop at 3 meter, followed by a slow ascent to the surface. So you are right, it is desirable but not mandatory. Same as a safety stop basically.
If you follow the desired / encouraged slow ascent, it will better match any theoretical model used to create the ascent protocol. After all, somebody somewhere thought it was a good idea to ascent like that.
quick edit: if an agency goes through the trouble of creating an ascent protocol that differs from most other agencies, they probably have their reasons. Following the recommendations of the protocol means you respect those reasons as much as possible, even if they are not mandatory.
I fully agree with you that the recommendation should be followed. However, GUE's Rec book "Beginning with the End in Mind" recommends 1 minute from 3m to the surface not 3...