Vyper and Nitex Q vastly different on NDLs

[raftingtigger]

I am currently using 2 computers in my OW rec depth dives. My primary is a fully unlocked DiveRite Nitex Q with standard settings and my back-up is a Vyper (nitrox) on standard conservatism. The Nitex is MUCH more conservative than the Vyper, but until my last dive it wasn't apparent how different they were.

About the 55 min mark on this dive my Ni Tek started me into deco, with a maximum obligation of 3 min at 10'. At this maxiumum deco on the Ni Tek, the Vyper gave me 12 more minutes of NDL. I was very fat on gas (Nitrox 21) and had 2 independent cylinders (SM) so I let it run to see where it would go. Deco cleared about 70 min RT.

Clearly the conservativism and algorithims are set differently. I would like to adjust the Ni Tek a little closer to the Vyper. Any suggestions on settings? or should I just play with simulators. I understand the theory, but am weak on the execution of gradient factors. BTW, the Vyper is very close to tables and generic simulators. I have both the DivePal Tech and the V-Planner working right now.

Thanks in advance.

 

[RainPilot]

GF and the Suunto algorithm won't match, especially for repetitive diving. If you search for the terms RGBM and gradient factors you should find a couple of threads where this is discussed. Recently @DevonDiver posted some info he had where on the first dive it was something like 90/90 and the next div xx/60 or so IIRC.

The upshot is that there is no magic GF that will keep them in line, the underlying algorithms are just too different.

 

[raftingtigger]

The upshot is that there is no magic GF that will keep them in line, the underlying algorithms are just too different.

That is important info. Thanks RainPilot.

 

[RainPilot]

That is important info. Thanks RainPilot.

You are welcome, this thread is where Andy talks about the differing GF.

Gradient Factors and recreational diving

 

[raftingtigger]

RainPilot. That thread is spot on.

I have a week in Bonaire coming up and this gives me food for thought on setting my computers. I would like to maximize my available underwater time while doing my best for NO recompression rides. If I surface with both computers happy there is a good chance my body will be happy too.

 

[tbone1004]

dive rite default settings are as follows
CONS 2= 30/75 (default)
CONS 1= 40/100
CONS 0= 75/95

0 is going to be much closer to most tables and will likely be closer to the vyper for the first dive and much more forgiving on the rest of them. Of those I would personally leave it on 2 for most diving, but if doing NDL only diving, I'd put it on 0.

If you have custom GF options, which you should if it's fully unlocked, you can adjust it to whatever you feel comfortable diving. My personal GF's right now are 50/80, but that's for decompression diving. If I was doing recreational NDL diving it would probably be 80/90

 

[raftingtigger]

Thanks tbone.