Computer or Not

[meekal]

What I don't understand, is with the technology available today, so many computers still penalize you for time you spend offgassing. This is my only real knock against using them. If I dive to 100ft, and I spend time on deco at 50,40,30, and 20ft, the computer should NOT be penalizing me for that. It should be intelligent enough to realize that I am taking nitrogen out of my body.

Why do I need to spend $800 on a computer that can integrate deep stops, or has RGBM to do this? Until they come down in price, I'll stick with a depth guage or a comp in guage mode, and tables..

- that's why you do your homework (like me!) and get a SUUNTO (like me!) - even the lowest priced MOSQUITO uses the RGBM model. when you download the data to your PC and make all dem purty graphs you can play the dive like a VCR where on the NITROGEN loading graph; yes, it DOES show you offgassing as you come up from depth - but only in certain 'compartments' - [as noted elsewhere] - some of the "deeper" compartments continue to ON-gas.

 

[*Floater*]

I am curious about 90 mins at 60' and how people are feeling after that - esp. if they were doing 1 min stops.

No cheating by using the air setting.

That's in my PADI EAN32 table so I'm sure it's tried and tested by plenty of divers, though that table requires a 3min safety stop at 15 ft for this dive.

The NOAA EAN32 table gives 100 min at 60'.

http://www.ndc.noaa.gov/dp_forms.html

 

[nyprrthd]

My Oceanic VT Pro uses a modified Haldanean algorythym, which tends to be on the liberal side of dive computers. I take that into account while on a dive. The main reason that I got the Oceanic is that it has BIG numbers. Please reference this thread if you're not over 40: http://www.scubaboard.com/showthread.php?t=138835

 

[PerroneFord]

I don't need that info on a graph.. I need that info on my wrist...

-P

- that's why you do your homework (like me!) and get a SUUNTO (like me!) - even the lowest priced MOSQUITO uses the RGBM model. when you download the data to your PC and make all dem purty graphs you can play the dive like a VCR where on the NITROGEN loading graph; yes, it DOES show you offgassing as you come up from depth - but only in certain 'compartments' - [as noted elsewhere] - some of the "deeper" compartments continue to ON-gas.

 

[meekal]

I don't need that info on a graph.. I need that info on my wrist...

-P

it IS on your wrist.... i was replying to your original post that MOST computers DON'T calculate (give credit for) off gassing as you come up from depth. i was just stating that SOME do..... like the SUUNTO.... so when it calculates further dives and SI and NDL and such it HAS used this information in these calculations....

the VCR functionality on the purty graph on my PC is just the 'proof-in-the-pudding' that it IS doing the calculations....

 

[PerroneFord]

I'm well familiar with the SUUNTO. In fact, I'm about to order a vyper. I want a computer that can check me on ascent, and watch my pending SI decrease as I offgas underwater. So when I get on the boat it says, "you're clean". DIVE!

Got me?

 

[WarmWaterDiver]

- that's why you do your homework (like me!) and get a SUUNTO (like me!) - even the lowest priced MOSQUITO uses the RGBM model. when you download the data to your PC and make all dem purty graphs you can play the dive like a VCR where on the NITROGEN loading graph; yes, it DOES show you offgassing as you come up from depth - but only in certain 'compartments' - [as noted elsewhere] - some of the "deeper" compartments continue to ON-gas.

The software for my TUSA IQ-700 shows dynamic bar graphs regarding what each of the 12 theoretical compartments are loading / unloading throughout the dive profile. This uses 'faster' and 'slower' compartments based on half-times. I'm not sure what 'deeper' theoretical tissue compartments are, but I don't own Suunto DC's.
This uses Buhlmann algorithm, not RGBM - and I did my homework as well.

My NiTek3 used to be able to do the same (also Buhlmann algorithm, with 3 fewer theoretical tissue compartments). But my electronic logbook was hosed with Dive Rite's unfortunate events regarding PC software upgrades.

http://www.scubaboard.com/showthread.php?t=87372

No problem, the software for the TUSA model (and for the Apeks models, and the Cressi-Sub models, and the Scubapro Xtender) works fine for me. I always keep a paper log as well in case of PC issues.

Neither my IQ-700 nor my NiTek3 display what all the theoretical compartments are doing at all times during a dive though - just the controlling compartment at any point in time.

To each their own.

 

[darkpup]

The software for my TUSA IQ-700 shows the same graphs regarding what each of the 12 THEORETICAL compartments are loading / unloading throughout the dive profile. This uses Buhlmann algorithm, not RGBM - and I did my homework as well.

I was under the impression that the original Buehlman model had 4 compartments, Navy had 5, and Haldane had 14. I wonder if the model used by your computer is strictly Buehlman, or some new derivative of the original model.

Not that it matters, I'm just curious.

~ Jason

 

[WarmWaterDiver]

You can check the owners' manuals - all available on TUSA and Dive Rite web sites. The Dive Rite model owner's manuals cite 9 theoretical tissue compartments and a Buhlmann algorithm for quite a number of years (and models). The TUSA (and Apeks, etc. - BTW, the English version Apeks manual is better than the TUSA English version manual) cite 12 tissue compartments and a Buhlmann based algorithm. The Cressi-Sub manual English translation is a bit spotty, but I infer they have progressed from 9 tissue compartments and a Buhlmann algorithm in the 1 mix Archimede to 12 tissue compartments and a different Buhlmann algorithm in the 2 mix Archimede.

The only DC I've seen reviews on recently that used 4 theoretical tissue compartments were the Citizen models - and they use a DCIEM algorithm IIRC.

 

[rjack321]

I think Buehlman originally had 16 compartments. Oceanic and derivatives use a 12 compartment Haldane model.

"Suunto RGBM" is actually pretty close to a Buehlman model, its apparently not the same as Wienke's full blown RGB model. The only computer I've heard of using the latter is the VR3 with a very expensive upgrade. I have only heard negative comments about how long it stretches out deco.

Maybe someone here is using a $1500-1800 VR3 for recreational profiles. I'd be interested in seeing how those NDLs compare.