What's your Low Gradient Factor Selection

Which Low Gradient Factor are you using?

  • 0-10

    Votes: 6 3.1%

  • 11-20

    Votes: 17 8.7%

  • 21-30

    Votes: 58 29.7%

  • 31-40

    Votes: 61 31.3%

  • 41-50

    Votes: 28 14.4%

  • 51-60

    Votes: 7 3.6%

  • 61-70

    Votes: 3 1.5%

  • 71-80

    Votes: 6 3.1%

  • 81-90

    Votes: 8 4.1%

  • 91-100

    Votes: 1 0.5%
  • Total voters
    195
Tmccar1

Tmccar1

Tech Instructor/ Capt
Thought with the latest public deco shake up it might be interesting to put a poll together to see what people are using... Mainly those who are using other than standard Gradients. I seem to be hearing more and more people using matching low/high or higher than standard (meaning what their computer comes with) low numbers.
 
Last edited:
problem with what some may say , is thay never tell you what other fudge they are using or the sort of depth runtime gas mix in use , number of good out comes and a shit load of other stuff that could come into play ,


ill hang back for now see what s posted ,
good look
 
Mr fish said:
problem with what some may say , is thay never tell you what other fudge they are using or the sort of depth runtime gas mix in use , number of good out comes and a shit load of other stuff that could come into play ,


ill hang back for now see what s posted ,
good look
Click to expand...

Totally agree. It's more an exercise for now. I'm hearing a lot of people using 70+ low GF's but nobody is really talking about it publicly. I hope that this is an ice breaker for them to come out and discuss it without being condemned or condoned.
 
I just sent a week diving the repulse. I always use 15/85 tried 30/80 due to current research. Got out the water feeling really crap. Went back to 15/85 and the crapness went away

Sent from my Nexus 5 using Tapatalk
 
Tmccar1 said:
Thanks for sharing Don! How long have you been using them? Any issues along the way?
Click to expand...

I started with 10/100 and had niggles after every dive, switched to 10/95 and all ok. later jumped to 30/90 without issue, next jump to 50/90 without issue, next was 70/90 and still fine. I used 70/90 for about 6 months before going to 80/90 for a few tries. I still prefer 80/90, but very few of my buddies are that aggressive and I attempt to stay with them for deco and safety reasons. I have never been able to notice any consistent difference in how I feel from them though. I have not had any dives that I felt crappy from since dropping the high GF down from 100.

I also believe in very fast ascents to my first deco stop of anything below 200'.
 
I find it amusing that people are "interested" or mildly horrified by others using a high low GF and avoiding deep stops... its what we did for years (decades even) before deep stops came along without issues, good old Bend & Fix profiles, the evil that was ProPlanner etc. A slower ascent and even the odd deeper stop maybe makes you feel a little less knackered later in the day (sub clinical reduction?) but its highly subjective.

I do a smattering of deeper stops on a slower ascent because- its easy, no time pressures we used to have on OC and waiting for other CCR divers trying to maintain PPO2 :amstupid: That said amongst my laminated cut tables for OC bailout I have a set of full speed old-skool Bend-o-matic stops, up fast and long shallow hang, because they are easy, minimize time pressures and its easier to get help from the boat at 6-15mtrs compared to 30-40mtrs!

There's a bunch of ways to skin a cat, pick the GF's that suit you and/or your buddy but understand that you can safely skip them all if the sh*t hits the fan- the most important thing to know is the Minimum possible stops, anything other than a direct ascent is padding technically speaking :chuckle:
 
Ran 30/85 for years with additional padding deep. In hindsight, slight niggles occurred after not doing enough time shallow. I now put those deep stops into the shallow time. 45/85 without mods is a good compromise for me at the moment.


Sent from my iPhone using Tapatalk
 
The other lesson we learnt is that scooters for deep diving with a workload is mandatory, not a nice to have. We bent 3 out of 4 on a 75m dive pulling up and down the line. The guy not bent was on a scooter. We repeated the same profile regularly on scooters with zero issues.


Sent from my iPhone using Tapatalk
 
Ben Field said:
I find it amusing that people are "interested" or mildly horrified by others using a high low GF and avoiding deep stops... its what we did for years (decades even) before deep stops came along without issues, good old Bend & Fix profiles, the evil that was ProPlanner etc. A slower ascent and even the odd deeper stop maybe makes you feel a little less knackered later in the day (sub clinical reduction?) but its highly subjective.

I do a smattering of deeper stops on a slower ascent because- its easy, no time pressures we used to have on OC and waiting for other CCR divers trying to maintain PPO2 :amstupid: That said amongst my laminated cut tables for OC bailout I have a set of full speed old-skool Bend-o-matic stops, up fast and long shallow hang, because they are easy, minimize time pressures and its easier to get help from the boat at 6-15mtrs compared to 30-40mtrs!

There's a bunch of ways to skin a cat, pick the GF's that suit you and/or your buddy but understand that you can safely skip them all if the sh*t hits the fan- the most important thing to know is the Minimum possible stops, anything other than a direct ascent is padding technically speaking :chuckle:
Click to expand...

Thanks for sharing. So that said what did you decide to use for GF's (assuming that's what you're using) for OC and/or Closed?
 
Last edited:
I normaly dive in the 50-80m zone for 120mins (sub 10c water) -180mins (+ 10c water max 16c) on average and ocasionaly up to 240mins total run time

have been progressing up the GFs recently and currently run 50/85

Generaly ill be diving 16/50 or 14/65he and i finish deco on pure 02 for the last 20mins


I will be progressing to 70/85 this year where ill probably stop


ATB

Mark
 
Tmccar1 said:
Thanks for sharing. So that said what did you decide to use for GF's (assuming that's what you're using) for OC and/or Closed?
Click to expand...

CC only, 40/85 recently, considering trying higher.

I assume people also change their GF's depending on max depth, workload, water temp etc, I doubt one pair of figures is ideal for all scenarios?
 
I'd caution against simply removing the deep stops rather than redistributing the time to shallower depths, i think that's probably reading abit too much into the NEDU study. That said it's the high GF number that dictates the majority of the deco anyway.

I've got an excel spreadsheet (linked below) that will compute run times and total tissue supersaturation for a large range of Gradient factors for a given depth and time. You can play about with different dil's, bottom times and most importantly time on the surface post dive to see how they change things.

http://bit.ly/QCvyew
 
nobody said:
I'd caution against simply removing the deep stops rather than redistributing the time to shallower depths, i think that's probably reading abit too much into the NEDU study. That said it's the high GF number that dictates the majority of the deco anyway.
Click to expand...

Surely if you remove deep stops from an active calculation the algorithm automatically creates longer shallow stops? You'd need to be pretty dumb to cut deep stops tables then ignore some of them :dunce:
 
nobody said:
I'd caution against simply removing the deep stops rather than redistributing the time to shallower depths, i think that's probably reading abit too much into the NEDU study. That said it's the high GF number that dictates the majority of the deco anyway.

I've got an excel spreadsheet (linked below) that will compute run times and total tissue supersaturation for a large range of Gradient factors for a given depth and time. You can play about with different dil's, bottom times and most importantly time on the surface post dive to see how they change things.

http://bit.ly/QCvyew
Click to expand...

Very nice spread sheet. After looking over the stops on the far left of the page I notice that the stop ended at 42 feet for the dive plan I ran. Am I missing a step or reading it incorrectly. Thanks for posting this, I think it is a great planning tool.
 
nobody said:
I'd caution against simply removing the deep stops rather than redistributing the time to shallower depths, i think that's probably reading abit too much into the NEDU study. That said it's the high GF number that dictates the majority of the deco anyway.

I've got an excel spreadsheet (linked below) that will compute run times and total tissue supersaturation for a large range of Gradient factors for a given depth and time. You can play about with different dil's, bottom times and most importantly time on the surface post dive to see how they change things.

http://bit.ly/QCvyew
Click to expand...

Love the disclaimer!
 
zirk said:
Very nice spread sheet. After looking over the stops on the far left of the page I notice that the stop ended at 42 feet for the dive plan I ran. Am I missing a step or reading it incorrectly. Thanks for posting this, I think it is a great planning tool.
Click to expand...

What plan did you run? Because this has evolved slowly since about 2006 when i first got interested in diving i only used a few rows to check i was getting vaguely sensible times. On a deep, conservative plan it probably just ran out of space. I'll try and eliminate that problem next version.
 
You must log in or register to reply here.
Back
Top