Are Suunto Zoops super conservative?
- Thread starter Alex Locke
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"We get it, we just don't want it": the point is not that I misunderstand the diagram, the point is that I don't see any reason to believe that chosen data points accurately represent the reality of a dive computer during a dive.
We're making progress here. We've gone from "I don't understand it" to "I don't believe it."
All you see in a diagram like that -- or in the table I posted a few post above -- is the planning mode output of the computer, or the last row on a table. It assumes a square profile, and a particular depth and bottom time. It is a way to compare computers or tables. It turns the computer into a table, in fact. No table ever match a real dive. No planning output from a computer ever matches a real dive. So, you are absolutely correct that the graph shown -- or the table I provided -- accurately represents the reality of a real dive..... But does that invalidate the intercomparison of tables, or computers? By your argument, all tables are nonsense too. Do you really think that?
Without stirring this particular pot any more than necessary, let me correct what I believe this graph is showing. You guys are arguing about apples and oranges. You both have valid points but have made some small mistakes in interpreting what you are seeing.
The NDL for my Uwatec set at most liberal is 15 min at 100'
This graph shows that after 7 min at 100 feet, I have about 8 min NDL left. Other computers give you more or less.
I believe that @dmasiuk is correct that this graph is indeed showing SOME points on a multilevel dive. If I ascend to 90 feet and spend a couple more minutes there, I get the benefit of a little more NDL: while I have a little more bottom time, I still have ~8 min left of NDL. All the computers are clustered fairly tightly here.
If I then ascend to 60' all computers provide the benefit of an increasing NDL, and if you continue your dive to a bottom time of 26 min, the NDLs of the various models begin to diverge. If you dive some more and by 42 min then ascend to 40 ft, the divergence becomes significant.
For this arbitrary dive (and yes, it doesn't say when the depth transitions were made, but we assume the simulations were identical among computers) then you can use this divergence to determine how your computer compares with others.
That's all.
I think it's valuable info, and I'm glad of my choice of Uwatec for no stop diving. In fact, I dive it at microbubble L4 for added conservatism (and yes, shorter dives). The microbubble "stops" at L4 begin to approach a Buhlmann GF that I could accept for technical diving when I compare gas plans. But don't read more into this than is there, please.
For this arbitrary dive, you can see how various algorithms diverge. YMMV.
That's okay. Are you happy with your computer? If not would you be tilted toward another based upon the liberal vs. conservative that you see in this graph?
I sure would. I'm older, and there's no way I'm choosing a DSAT algorithm brand.
But it's probably moot for technical diving, since we'll likely choose a brand that doesn't hide its calculations behind proprietary models. That's why Shearwater is cornering the market.
The NDL for my Uwatec set at most liberal is 15 min at 100'
This graph shows that after 7 min at 100 feet, I have about 8 min NDL left. Other computers give you more or less.
I believe that @dmasiuk is correct that this graph is indeed showing SOME points on a multilevel dive. If I ascend to 90 feet and spend a couple more minutes there, I get the benefit of a little more NDL: while I have a little more bottom time, I still have ~8 min left of NDL. All the computers are clustered fairly tightly here.
If I then ascend to 60' all computers provide the benefit of an increasing NDL, and if you continue your dive to a bottom time of 26 min, the NDLs of the various models begin to diverge. If you dive some more and by 42 min then ascend to 40 ft, the divergence becomes significant.
For this arbitrary dive (and yes, it doesn't say when the depth transitions were made, but we assume the simulations were identical among computers) then you can use this divergence to determine how your computer compares with others.
That's all.
I think it's valuable info, and I'm glad of my choice of Uwatec for no stop diving. In fact, I dive it at microbubble L4 for added conservatism (and yes, shorter dives). The microbubble "stops" at L4 begin to approach a Buhlmann GF that I could accept for technical diving when I compare gas plans. But don't read more into this than is there, please.
For this arbitrary dive, you can see how various algorithms diverge. YMMV.
That's okay. Are you happy with your computer? If not would you be tilted toward another based upon the liberal vs. conservative that you see in this graph?
I sure would. I'm older, and there's no way I'm choosing a DSAT algorithm brand.
But it's probably moot for technical diving, since we'll likely choose a brand that doesn't hide its calculations behind proprietary models. That's why Shearwater is cornering the market.
I'm sorry to get this explanation. I was incorrectly defending you, and withdraw that defense.Without stirring this particular pot any more than necessary, let me correct what I believe this graph is showing. You guys are arguing about apples and oranges. You both have valid points but have made some small mistakes in interpreting what you are seeing.
The NDL for my Uwatec set at most liberal is 15 min at 100'
This graph shows that after 7 min at 100 feet, I have about 8 min NDL left. Other computers give you more or less.
I believe that @dmasiuk is correct that this graph is indeed showing SOME points on a multilevel dive. If I ascend to 90 feet and spend a couple more minutes there, I get the benefit of a little more NDL: while I have a little more bottom time, I still have ~8 min left of NDL. All the computers are clustered fairly tightly here.
If I then ascend to 60' all computers provide the benefit of an increasing NDL, and if you continue your dive to a bottom time of 26 min, the NDLs of the various models begin to diverge. If you dive some more and by 42 min then ascend to 40 ft, the divergence becomes significant.
For this arbitrary dive (and yes, it doesn't say when the depth transitions were made, but we assume the simulations were identical among computers) then you can use this divergence to determine how your computer compares with others.
That's all.
I think it's valuable info, and I'm glad of my choice of Uwatec for no stop diving. In fact, I dive it at microbubble L4 for added conservatism (and yes, shorter dives). The microbubble "stops" at L4 begin to approach a Buhlmann GF that I could accept for technical diving when I compare gas plans. But don't read more into this than is there, please.
For this arbitrary dive, you can see how various algorithms diverge. YMMV.
That's okay. Are you happy with your computer? If not would you be tilted toward another based upon the liberal vs. conservative that you see in this graph?
I sure would. I'm older, and there's no way I'm choosing a DSAT algorithm brand.
But it's probably moot for technical diving, since we'll likely choose a brand that doesn't hide its calculations behind proprietary models. That's why Shearwater is cornering the market.
I now find your graphic, upon reflection, to be quite uninformative and not really useful.
It describes an imaginary dive, without telling me what the dive is.
It apparently conflates Pelagic PZ+ with RGBM.
It is impossible to understand without your additional explanation, which seems self-contradictory.
It has at least one major typo in it, are there more? How would I know?
Did your write your own algorithms to make this graphic? Surely you can't get what you have there from any planning mode.
@dmaziuk I apologize. I don't agree with your specific criticism, (the lines for example) but I agree the graphic is not what it appears to be.
Lol. Just go to the simplyscuba link at the top of the graph and see if you conclude something else than I did. I had to figure out what they were trying to show, too!
Couldn't get further than the first level in this "dive" on my computers planning mode, and guessed at the rest of what they were trying to show.
I'm not defending it at all. It's very simplistic. If it is indeed a theoretical multilevel dive, it is showing what you both know occurs with different algorithms.
It's not conflating Pelagic with RGBM. It's merely showing that at some point in this particular dive, there's an overlap between algorithms.
More important, I think it's showing a divergence that confirms a certain conservatism in my Uwatec. That's why I shared it. I'm not wedded to this, nor do I want to fight with you about the particulars.
I just thought that it was interesting.
Couldn't get further than the first level in this "dive" on my computers planning mode, and guessed at the rest of what they were trying to show.
I'm not defending it at all. It's very simplistic. If it is indeed a theoretical multilevel dive, it is showing what you both know occurs with different algorithms.
It's not conflating Pelagic with RGBM. It's merely showing that at some point in this particular dive, there's an overlap between algorithms.
More important, I think it's showing a divergence that confirms a certain conservatism in my Uwatec. That's why I shared it. I'm not wedded to this, nor do I want to fight with you about the particulars.
I just thought that it was interesting.
Following your explanation, Mares will change the NDL from 18 minutes at 40 feet/42 minutes into the dive, to infinity at the surface 50 minutes into the dive. Does it mean your Mares considers you completely off-gassed during a 15-minute 3 fpm ascent after a 50-minute dive? The final "data point" is absolutely correct, BTW: your NDL on the surface is infinite.
Don't you see: if you stay at 40 ft after your 42-minute dive, and your Mares won't recalculate the NDL, then the Mareses NDL is only 18 minutes. But it will recompute, that's what it does. That's what makes the comparison meaningless: fixed points are not representative.
Since we both agree that computers recalculate on the fly, if two brands consistently give different NDLs, by whatever imaginary dive they used to arrive at that data point, it IS meaningful.
It just isn't quantifiable.
ALL it says is that one computer/algorithm is more "conservative" than another. I thought it was useful to share. I think I'm done now.
It just isn't quantifiable.
ALL it says is that one computer/algorithm is more "conservative" than another. I thought it was useful to share. I think I'm done now.
OK, I went to the simplyscuba link and read the article containing the graphic. It provides no information whatsoever about what the graphic means, but the inference is that it is a comparison between the DSAT and the PZ+ algorithms used by Oceanic. I have no idea how they calculated their data points; they may be completely made-up for all I know. Basing a choice of UWATEC on that graphic is silly. I would never even repost that graphic; it is useless.
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