Rgbm

[acqua]

i read different opinion about rgbm model
yuor opinion

 

[Greg Barlow]

The RGBM has received quite a bit of documented research through NAUI (and others). At this point in the data collection, it appears to be a very effective model. There are a number of dive computer manufacturers that have implemented the program into their units.

Greg Barlow
Former Science Editor for Rodale's Scuba Diving Magazine

 

[neonstingray]

Mark Ellyatt (one of the deep diver record holders) has some interesting info on his site. He thinks the model isn't too good in its present state, but so far has been ok for most divers because the mainstream computers using it now are using a version so conservative that the algorithm becomes more like the standard conservative plans that computers have been using. He's worried that the model hasn't been tested enough, and is being used more as a marketing gimmick.

http://www.inspired-training.com/RGBM Really Good Bends Model.htm

-Austin

 

[Diver0001]

First of all, welcome to the board.

i read different opinion about rgbm model
yuor opinion

A few from the hip thoughts:

- The premise and workings of the model account for real world physics better than the Haldane/Buhlmann models.

- It's much harder to grasp the details and/or harder teach than Haldane.

- Not suprisingly the results it produces within the NDL's are comparable. Within the NDL's the model discussion is pretty much moot.

- Once over the NDL's the RGBM model gives some surprising results, namely deeper and often faster decompression lines than Buhlmann. There has been no formal testing of the model but some people have the big-hairys needed to just go out and dive it and the results seem promising, although some tuning may still be needed.

- In either case I would think that the majority of tek divers are now using some kind of bubble model, either RGBM or VPM-B.

- In reality most computers that claim to use RGBM (like the Suuntos) are really using a modified Haldane that people refer to as "bubble wrapped Buhlmann". This is a sort of fence sitting that may be related to liability or the high cost of licencing RGBM.

- If something isn't done about the licencing costs then market penetration will remain limited and manufacturers will continue to invent new forms of bubble wrapped Buhlmann or start putting VPM-B into computers.

So....in short.....it works, it works best over the NDL's and it's expensive.

R..

 

[BigJetDriver]

RO,

Excellent analysis of the RGBM versus Haldane/Buhlmann situation. Pretty good shooting from the hip!

I would add, however, that the NAUI technical test teams, and the U.S. NEST teams have an impressive amount of man-dives on the algorithm, with no major problems.

 

[DiveGolfSki]

- In reality most computers that claim to use RGBM (like the Suuntos) are really using a modified Haldane that people refer to as "bubble wrapped Buhlmann". This is a sort of fence sitting that may be related to liability or the high cost of licencing RGBM.

I know of two that claim RGBM, the Suuntos, as you said, and the Dacor Darwins. I have the latter but have sold it (for reasons not related to the model or the make ... numbers are tooo small for old eyes). As such, I'm looking into getting the Suunto's but if they too are not fully RGBM, why bother. I currently dive the RGBM tables as published by NAUI but I'm curious as to how close these computers follow the tables?

More information on the RGBM can be obtained directly from Wienke's site:

http://www.rgbmdiving.com/index.htm

 

[BigJetDriver]

DiveGolfSki,

Here's the best RGBM wet-computer: H-S Explorer

Great display! Your choice of RGBM or Buhlmann, and conservatism settings.

Here: www.hs-eng.com

P.S.--How many sports addictions do you have??

 

[neonstingray]

So the articles on Ellyatt's site don't make any of you guys question how good it really is? Just wondering, because no one had any comments on the major problems he had after I posted that link.

-Austin

http://www.inspired-training.com/As...using a combined decompression model V1_6.pdf

just another article on his site, if you guys are bored.

 

[DiveGolfSki]

DiveGolfSki,

Here's the best RGBM wet-computer: H-S Explorer

Great display! Your choice of RGBM or Buhlmann, and conservatism settings.

Here: www.hs-eng.com

Thanks for the link ... busy little gadget isn't it.

P.S.--How many sports addictions do you have??

Too many (sailing, bowling ... a sport?, hunting, etc.). Wife drew the line on taking flying lessons ....

 

[Diver0001]

So the articles on Ellyatt's site don't make any of you guys question how good it really is? Just wondering, because no one had any comments on the major problems he had after I posted that link.

-Austin

http://www.inspired-training.com/As...using a combined decompression model V1_6.pdf

just another article on his site, if you guys are bored.

It's hard to grasp if the issues he is encountering apply at all to shallow dives (which to him is dives under 50 metres). His frame of reference is so different to what you or I would call diving that I'm not sure we can draw the parallel. I mean, the guy makes huge bounce dives with 26 stage bottles..... That's not diving in any sense that I can relate to.

Moreover, he says he's been bent every time he's used RGBM. There is a disconnect here because he seems to be one of the few (if not the only one). It makes me wonder if he isn't just particularly sensitive, which would be very ironic being the depth freak that he is.

I did find this quote interesting, however: "4. The bubble model hypothesis that by carrying out many ‘bubble controlling’ deep stops early in the ascent profile, negates
requirement to carry out long duration ‘slow tissue’ shallow water stops, is not confirmed by man testing evidence."

That's food for thought and an area where I think more scientific testing is needed.

R..