Gradient Factor Presets by Manufacturer/Computer

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

That's why the algorithm itself is a relatively minor part of a system design. You have to design for a user base and so on and so forth. Shearwater's target user base may be people whose gear will kill them in 4 minutes if they aren't careful, so what their computer does not do may be OK with them. There's a problem with selling a design like that to us clueless vacay divers: one day you may get class-actioned by some concerned mother in California.

I think it is more than that. Yo are correct regarding shearwater but in their behalf newbys dont but them. they do buy others and they have conservative settings and newbys are of the generation that will rig anything to get something free. You wnat to watch free Tv and some kid will bring in a paper clip and poke it somewhere and presto you have pay for view for free, Likewise these new divers will,,, even if they can not define a gf ,, use it to get as much dive time possible and not know the reprocussions of their acts. They dont know because they are not taught. So all computers have the problem of being dangerous if misused. I emphasize the word mis used.
 
Yo are correct regarding shearwater but in their behalf newbys dont but them.

Only if they don't read ScubaBoard. If they do something stupid like omit mandatory deco and come here whining about their suunto locking them out, do you think they'll get the "shiny terics never do that!" as the 2nd answer, or third?
 
Only if they don't read ScubaBoard. If they do something stupid like omit mandatory deco and come here whining about their suunto locking them out, do you think they'll get the "shiny terics never do that!" as the 2nd answer, or third?

I have absulutely no clue what you are talking about, or in what context. something has gone on a left turn here. scubaboard is not that popular, especially among new divers. Let me run a recap of my comments.

1. there is a significant difference in NDL's on various computers.
2. reason is conservative factor settings used the computer
3. research into how conservatism is being done in compiuters is with using time depth or gf's
4. request was made for a table of sorts to identify the low med high equivilant gf's used in different models and makers. someone on here provided that.
5. questions asked by basic recreational ow's do not get their quesitons answered because they ask a recreatoinal question and get technical 200 ft diver answers. as result
6. because of no training in ow courses on the most fundimentals of deco or how to use tables or a computer,,, it results in newbys using the conservatism setting as a tool to control how long they can stay down.

This is where I am in the conversation. so again I do not understand you comment as it relates to it.

I pretty well have things down to explain to those I cross paths with or frequently dive with. It is amazing that you can ask a 10 year experienced diver what the conservative settings do and you get an italian salute. Most say what settings. others say I dont know. And then there are those that say they use the low setting because it lets them dive the longest. Some regurgitate the gf lo function as if it applies to rec diving. Hardly any one knows what micro bubbles are or if they are a threat of any kind. all they know is that they can go straight to the surface if they have to but should do a safety stop. Many think a safety stop is mandatory.
 
What you are implying is that 20/80 = 80/80 = 95/80 (an inverse GF); essentially the decompression profile doesn’t matter because you get out of the water at 80% regardless.
Divers, I apologise if I created some confusion with the above statement. I am specifically addressing decompression dives. For NDL dives, these GF pairs are the same because only GF-hi plays a role in NDL diving. GF-lo is not a factor. For those reading this thread but are unaware; @Jay_Antipodean started a thread that specifically addressed this question and the answer is NDLs are not affected by GF-lo.
On a NDL dive, which computers' NDLs are not affected by GFLo?

Also I mention 95/80 as an inverse GF. To my understanding there is no current dive computer that allows you to set an inverse GF but you can in Subsurface using its dive planning module.

Therefore I agree with @KWS final comments below and that for NDL diving 40/85 is the same as 85/85 and the only difference between 85/85 and 100/100 within NDL diving is that 85/85 generates a shorter NDL time limit.
So 40/85 is no different than 85/85 on ascents prior to NDL. and that 85/85 is no different than 100/100 prior to hitting NDL with the exception of ndl TIME CALCULATION.
 
Do you also believe that multi-level profiles are dangerous?
No, I don't believe multi-level profiles are dangerous. My multi-level profiles are done within no decompression limits. Typically the decompression dive I'm referring to is a planned deep dive with a specific objective like a wreck dive. These tend to be a square profile (more or less) and then up the shot line with the main objective to decompress rather than swim around and possibly get disoriented in blue water.
 
Why is this so complicated?
GFlo is irrelevant until you hit NDL. It could be anything.
Its complicated because dive computer designers made it so. YOU get it but 9/10 divers don’t. Your typical diver doesn't understand gradient factors. And @KWS and @dmaziuk have expressed the same sentiment. That is why @Jay_Antipodean asked the question regarding GF-lo's impact on NDL. Thank God Neptune for this forum so we can share knowledge and learn together! Hopefully scuba manufacturers monitor these types of threads so they get ideas on how to improve their equipment. And before @dmaziuk says it, I will on his behalf.:)
Yeah, good luck with that.
Just dovetailing back to the theme of this post about Presets. Some dive computers like Shearwater and now Mares offer both Rec mode and Tec mode. By and large, divers will assume Rec mode is for NDL diving. So why complicate the settings with GF-lo? Why not use the KISS principal; Keep It Simply Scuba. One of my original questions was; If you were responsible for specifying 3-6 presets for a new computer, what would they be?

Here is my recommendation for a dive computer’s Rec and Tec modes. For Rec mode there would be 3 Presets and a custom setting. The Presets would be 90, 80, 70 and a custom option set by the diver would range from 95 to 50 in one percent increments. These are GF-hi settings. No mention of GF-lo. The diver would not be able to set a GF-lo and it would not be displayed in Rec mode. GF-lo would be “flat” meaning it would be equal to the GF-hi setting.

So if a diver selects “80”, in the background it is really 80/80. And if the Rec diver goes into light deco, it would follow the decompression profile of 80/80. Of course the DC manufacture could add additional conservatism by padding the final stop by adding time; say an additional 5 to 15 minutes based on previous dives, profiles or fast ascents. Excluding GF-lo simplifies Rec mode.

What about Tec mode? This is where the concept of GF-lo comes in. There would be a custom setting for both GF-lo and GF-hi. I probably wouldn’t offer any Presets in Tec mode. The diver would be solely responsible for setting the Tec mode. That would be the basics of it; other bells and whistles could be added like a GF bailout mode etc.
 
I dont know where the gf lo should be for a rec diver. I would assume that if any one did , with no intention , go into deco it will not be a big deal health wise. If a setting had to be made for a gf Lo it would probably be just as well be a much higher value. With rec diving if you exceeded it at say 100 ft then you air is already getting low. allowing the shallowest possible stop would be critical to completing the stop called for. I would guess a value of 50 or better would be ok depending on your consumption. Then again you could just skip the stop all together depending on the conservatism setting. Bad precedent to suggest , but after all if you are barely in deco because you used a med setting. One could logically say that if you used a more liberal setting you would never have triggered the deco limit in the computer and thus you could say the computer is in deco but the diver is not.
 
Then again you could just skip the stop all together depending on the conservatism setting.
I hope you are not saying to ignore the computer and skip a mandatory deco stop. Even if it is "OK" for the diver, if the computer is "in deco" and you ignore it, MOST computers will lock you out for 24-48 h.
 
I probably wouldn’t offer any Presets in Tec mode.
Maybe one ought to distinguish between a "preset" and a "default. " In Tec mode you do need a default, otherwise the computer is not usable. The 30/70 used by Shearwater is fine....as a default. At least the computer will work. Feel free to change it.
So I see no problem with a manufacturer supplying a computer with a default setting, even in Rec mode, like the 40/85 (Medium Conservatism) Shearwater uses. If the new user just uses the computer without changing anything. he/she will probably be OK. Perhaps it would be even better to supply it with the default being High Conservatism (35/70).
 
I hope you are not saying to ignore the computer and skip a mandatory deco stop. Even if it is "OK" for the diver, if the computer is "in deco" and you ignore it, MOST computers will lock you out for 24-48 h.


what I am saying is that the computer does not say what the condition of the diver is. Only a result of a algorythme . I am saying that the odds of safely skipping a deco stop is pretty high when you mis configure your computer. example low conservative setting ndl is 18 and high is 10 you are set at high and you hit 11 minutes. the only reason you are in deco is because of the computer setting not the physiology of the diver.
If given a choice of skipping a stop or running OOA, you skip the stop. For those divers that think a little conservatism is good , there fore a lot is better,,, then you cause nothing more than computer problems for your self. Too many do not know how to use their puters. They use it in the config that came out of the box. In these aspect many divers are completely ignorant with their tools. And a computer is just that a tool. Not one to be blindly followed, but one that should be giving you the best advice it can. garbage in garbage out.
 
https://www.shearwater.com/products/peregrine/

Back
Top Bottom