Gradient Factors - What is Everyone Using?

[PfcAJ]

I dive to 30' max solo. "gradient"-- what's that? Yes, I HAVE a computer. I usually use my WATCH and depth gauge.

Hot take ^

 

[helodriver87]

60/80. The GF low isn't a huge issue on most of my dives. I only really notice it on longer trimix dives, where I'll end up with a first stop 20, maybe 30 ft shallower than my buddy. GF high has been a result of personal experience. I took a type 1 hit awhile back while diving GF high of 85. I scaled it back a bit and added a slow ascent from 20. Seems to be working so far, but it'll likely change again with more experience and training.

 

[macado]

50/85 for decompression dives has served me well for last 5 years so I haven't really had a reason to change, before that I *think* I ran 40/80 so not a huge change. My standard disclaimer has always been what works for me may very well bend someone else so your mileage may vary.

If I feel there were other factors during the dive (working hard, cold, tired, not feeling great), I will pad my last GF-Hi to 75-80 but otherwise I always feel comfortable getting out of water with 50/85.

Typically two dives a day in the 150-220ft range (45m-67m) in 39-42f (~4c) water. Runtimes vary from 80-120 minutes with minimum 90-120 minute surface interval.

 

[Fastmarc]

On the Perdix I use the Rec low conservative 45/95.
I do not go into deco.

 

[scubadada]

I hope everyone realizes that on a recreational, NDL dive, the first GF number does not mean a whole lot.

In fact, the GF low means nothing for a no stop dive

Sorry @tursiops I hadn't gotten to your post yet, I should have known

 

[boulderjohn]

50/85 for decompression dives has served me well for last 5 years so I haven't really had a reason to change,

You hear this a lot, and to a certain extent pretty much everyone has this approach to some degree. The problem is you have no way of knowing how well it is working for you. There is a range of GFs that will work for you, and you have no way of knowing after a dive where you were on that range. You may have been near the edge of DCS on every one of those dives and didn't know it.

I have used 50/85 a whole lot in the recent past. I was using that setting the day I did two dives with very light deco (2 minutes) and doubled my deco time on each. I gave those settings a lot of thought while I was in the chamber. I still don't think they are all that bad, but....

 

[scubadada]

This is an interesting thread. You would think that an individual response would largely be dictated by the type of diving, personal experience, and knowledge of the topic.

Ninety five percent of my diving is no stop, often quite aggressive. The other 5% is light, back gas deco, almost always <10 minutes. I have dived an Oceanic computer running DSAT as my primary computer for 18 years, a few over 1900 dives. I have dived a number of different backup computers, Cochran, Oceanic, Dive Rite, and now, Shearwater. For the last 4+ years, my second computer has run Buhlmann with GF.

I have learned quite a bit about Buhlmann, and how it compares to DSAT. Of course there is no way to set Buhlmann so that it always runs very close to DSAT. At a GF high of 95, Buhlmann is nearly always more conservative than DSAT on the 1st dive, especially when deeper. However, Buhlmann often runs more liberally on repetive dives, especially when shallower.

For the last couple of years, I have been running my Buhlmann computer at GF 80/95. To solve the discrepancy between the computers, I follow the more conservative, they are generally not much different. Before or after a Buhlmann computer, I have never had a deco stop deeper than 10 feet.

I have always done at least a 3 min SS on no stop dives. For years, I extended this to 5 min if I was close to NDL. I always padded my deco stops with another 3-5 minutes. Now, my final ascent is controlled by the SurfGF from my Teric, generally, no higher than the mid-80s.

So far, so good. To my knowledge, I have never had an episode of DCS. Unless something changes, I do not anticipate a change in my strategy in the near future. Perhaps when I get old . The @boulderjohn story does give me pause, he is not the only one I know with an episode like that.

Good diving to all

 

[UCFKnightDiver]

You hear this a lot, and to a certain extent pretty much everyone has this approach to some degree. The problem is you have no way of knowing how well it is working for you. There is a range of GFs that will work for you, and you have no way of knowing after a dive where you were on that range. You may have been near the edge of DCS on every one of those dives and didn't know it.

I have used 50/85 a whole lot in the recent past. I was using that setting the day I did two dives with very light deco (2 minutes) and doubled my deco time on each. I gave those settings a lot of thought while I was in the chamber. I still don't think they are all that bad, but....

Sorry to hear you had DCS, hopefully you're doing better now. I'm curious, after the incidence of DCS, what GF settings do you currently run? Looking back in the thread, I don't think you said (unless I missed it).

 

[boulderjohn]

Sorry to hear you had DCS, hopefully you're doing better now. I'm curious, after the incidence of DCS, what GF settings do you currently run? Looking back in the thread, I don't think you said (unless I missed it).

For deco diving, usually 60/75, which is in the ballpark of my friends. If they want something a little different, I do whatever we agree on. For NDL dives, I will kick the GFhi up to 85, which is essentially what I did before. The difference is that I now pay attention to the surfGF readout, and I don't surface until the number is way lower. I keep the GF higher during the bottom part of the dive so that people don't freak out about my going into deco during the dive, and then I wait for the surfGF to get lower during the safety stop.

A couple years ago I mentioned in a thread that on NDL dives I don't bother changing the GFs from my tech settings, so I go into deco by a couple of minutes on NDL dives, knowing that if I took a minute to raise the GFs I would still be within NDL. An imbecile who had dedicated his life to making my ScubaBoard existence miserable went nuts on that, starting an entire thread about how I was irresponsibly advocating going into deco on NDL dives and should be banned from ScubaBoard. By raising my GFhi, I avoid dealing with such imbeciles.

 

[tursiops]

By raising my GFhi, I avoid dealing with such imbeciles.

That's all it takes? Cool, I'm going to go change all my GFhi to 99 right now!