Gradient Factor Presets by Manufacturer/Computer

[CandiveOz]

I thought I would ask first before doing the legwork myself. Has anyone compiled a table/spread sheet listing the different GF Presets by Manufacturer/Computer?

More and more manufactures are offering dive computers with gradient factors. Depending on the level of customisation, they may offer a combination of recreational and/or tech presets along with the ability to enter a custom setting. I am interested in the presets to determine if there is commonality or a trend to "standardize" certain GF ratios. And if there is, if possible, determine the reason behind why these GF ratio presets were chosen in the first place. For example, a certain GF ratio may generate a deco profile that is already well established as "safe" for a certain depth/bottom times for popular wrecks or dive locations etc.

If no comparative table exists, to save me some time searching through other posts and user manuals, if you have a moment, please post your computer's GF presets here and then a final table can be easily compiled and shared with everyone.

Thanks for your help.

 

[TrimixToo]

Shearwater ships with 30/70 for Perdixes and Petrels.

[Edit] in tech mode.

 

[scubadada]

So Shearwater is 45/95, 40/85, and 35/75

Ratio is 93/93, 90/90, 80/80, 75/75, 30/90, and 20/89

You posted Mares Genius
R0 – 85/85
R1 – 70/80
R2 – 60/70
R3 – 50/60

T0 – 30/85
T1 – 30/75
T2 – 25/60
T3 – 25/40

My Nitek Q is 30/75, 40/100, 75/95, and custom

That's all I know

Actually, Liquivision Lynx ran 100/100, 30/85, and 30/75 in tec mode. Rec mode was some proprietary setting "optimized" for rec diving

 

[NAM001]

So Shearwater is 45/95, 40/85, and 35/75

Ratio is 93/93, 90/90, 80/80, 75/75, 30/90, and 20/89

You posted Mares Genius
R0 – 85/85
R1 – 70/80
R2 – 60/70
R3 – 50/60

T0 – 30/85
T1 – 30/75
T2 – 25/60
T3 – 25/40

My Nitek Q is 30/75, 40/100, 75/95, and custom

That's all I know

Actually, Liquivision Lynx ran 100/100, 30/85, and 30/75 in tec mode. Rec mode was some proprietary setting "optimized" for rec diving

allow me to add that with the latest rev for shearwater yo also have to the option to insert your own custom preset in rec mode

 

[CandiveOz]

Thanks @scubadada
Interesting - a bit of a variance. I thought about the best way to display the data and decided to rank them using Mares as a template. I assigned a R = Rec or T = Tech setting to the other computers making the assumption that a GF-lo is 30 or less which may not be an actual reflection on how Technical divers are now diving due to the current studies in deep stops. I did make an exception for the Nitek Q 40/100 which doesn't follow this <=30 rule but I consider a Tech setting.

To sort the data, I used the logic which gave me the same ranking outcome for the Mares settings which was; first sort by GF-lo, highest to lowest and then sort by GF-hi, highest to lowest. I'll update the table as more computer presets are provided.

@KWS thanks for your comment regarding the Shearwaters. Obviously they received feedback regarding their presets which actually sit in the bottom half of the table due to the low setting for GF-lo.

 

[tbone1004]

@CandiveOz shearwater tec default is 30/80

 

[scubadada]

@CandiveOz shearwater tec default is 30/80

I also thought the tec default is 30/70 and 40/85 for rec

 

[tursiops]

I also thought the tec default is 30/70 and 40/85 for rec

This is correct.

 

[tursiops]

Thanks @scubadada
Interesting - a bit of a variance. I thought about the best way to display the data and decided to rank them using Mares as a template. I assigned a R = Rec or T = Tech setting to the other computers making the assumption that a GF-lo is 30 or less which may not be an actual reflection on how Technical divers are now diving due to the current studies in deep stops. I did make an exception for the Nitek Q 40/100 which doesn't follow this <=30 rule but I consider a Tech setting.

To sort the data, I used the logic which gave me the same ranking outcome for the Mares settings which was; first sort by GF-lo, highest to lowest and then sort by GF-hi, highest to lowest. I'll update the table as more computer presets are provided.

@KWS thanks for your comment regarding the Shearwaters. Obviously they received feedback regarding their presets which actually sit in the bottom half of the table due to the low setting for GF-lo.

View attachment 511165

There is a logical inconsistency in these rankings....referring to "R" values (presumably meaning recreational) and then using GF-lo as a sorting factor, makes no sense, because GF-lo is irrelevant for an NDL dive. I am making the assumption that recreational=NDL. Do you have some other definition?

 

[CandiveOz]

HI @tursiops
Ye "R" values refer to Recreational and "T" values refer to technical. If the sort criterial was purely based on NDL diving then you are absolutely correct, it should be sorted by GF-hi only. And this is a valid point for manufacturers to reconsider. If they are going to provide a "recreational mode" why not keep it simple and offer GF flat presets (eg. 85/85, 70/70). Ratio computers do just that.

But recreational or "non-commercial" scuba diving has moved on from pure NDL diving. Due to technology (dive computers), the availability of O2 and nitrox for deco gas and advanced diver training; non-commercial divers are now doing decompression or "light" deco. You can call them Tech divers if you want. In light of this fact GF-lo needs to be taken into consideration. Let's take 20/89 which is currently sitting at the bottom. Should it actually sit just below 90/90? Or should it really sit above it since some would consider it more aggressive due to the deep stop implication. I suppose another way to sort the data is to separate the Tech settings from the Rec settings and see what that looks like.