UTD and GUE protocol and procedural differences

[KMD]

For tech 2 there was no hard and fast rules of decompression. As much as people would like it to be, there is no secret decoder ring of deco or arcane knowledge. Pretty much everything you have learned in Tech 1 applies for tech 2. It's just... deeper...and longer... with more bottles...

(Which is not to say that I am advocating that people just go out and do dives they don't have the training for) The margin of error in tech 2 is much much smaller. Gas goes quicker, consiquences of "effing up" are typically more severe.


Me personally, on the shorter bounce type dives that people conduct in open water, I am not a big fan of the "lets figure out our deco plan at 70'" approach. There should be at least basic framework of a deco plan in place before the dive.

I don't want to conduct a dive start to get cold then get to the 70' stop and have my buddy throw up 15 extra minutes of O2 'cause thats what he likes to do. If I knew he likes longer deco beforehand, then I could shorten the bottom time rather than freezing my butt off.

That being said, the framework discussed can be very simple with divers one is comfortable diving with. Within our team it can be as brief as, "150 for 25 w/ 1:1 ratio, max deco of 35 minutes? Yes. Good lets go diving"

But with any unfamiliar diver (I don't care if they are UTE, GUE, AG-GUE trained, NAUI-tech, or any other agency or flavor) there is going to be at least a basic discussion of the dive plan before I splash. Devolping a large obligation and only to discover that yours and his deco plans are wildly divergent seems to be very foolish to me.

 

[rjack321]

That being said, the framework discussed can be very simple with divers one is comfortable diving with. Within our team it can be as brief as, "150 for 25 w/ 1:1 ratio, max deco of 35 minutes? Yes. Good lets go diving"

Are you counting the deep stops as "deco"? Or is there 10mins of fudge in there?

At least for us, we usually communicated Tech1 dives in terms of max deco - since we were on one deco gas that was fairly straightforward. But for 2 gas dives its more along the lines of "max 190, 25mins BT" and we understand the consequences of that and 'convert' into obligations in our heads and say something like "my lp85s aren't quite full enough for that, we can try but I might be turning early on rock bottom."

But with any unfamiliar diver (I don't care if they are UTE, GUE, AG-GUE trained, NAUI-tech, or any other agency or flavor) there is going to be at least a basic discussion of the dive plan before I splash. Devolping a large obligation and only to discover that yours and his deco plans are wildly divergent seems to be very foolish to me.

Seems that the whole point of the thread is to look at what some of these differences might be (amongst people who otherwise consider themselves "similar") :blinking:

 

[MXGratefulDiver]

I don't want to conduct a dive start to get cold then get to the 70' stop and have my buddy throw up 15 extra minutes of O2 'cause thats what he likes to do. If I knew he likes longer deco beforehand, then I could shorten the bottom time rather than freezing my butt off.

That being said, the framework discussed can be very simple with divers one is comfortable diving with. Within our team it can be as brief as, "150 for 25 w/ 1:1 ratio, max deco of 35 minutes? Yes. Good lets go diving"

But with any unfamiliar diver (I don't care if they are UTE, GUE, AG-GUE trained, NAUI-tech, or any other agency or flavor) there is going to be at least a basic discussion of the dive plan before I splash. Devolping a large obligation and only to discover that yours and his deco plans are wildly divergent seems to be very foolish to me.

Seems that the whole point of the thread is to look at what some of these differences might be (amongst people who otherwise consider themselves "similar") :blinking:

The group I do most of my tech dives with is a mix of GUE, UTD and NAUI-Tech. For the most part, it's like Kevin stated. We verbally walk through the dive plan and deco strategy and make an agreement on any divergences from the "standard" RD strategy. So far there's been only minor differences in how people want to approach deco ... mostly things like "let's spend an extra minute at 70 and 30" or "I'd like a couple extra minutes on the 20-foot stop" ... minor stuff like that. There's been almost no differences in terms of the length and depth of deep stops, shape of the profile, ratio setpoints, etc. Seems like everybody's close enough to the same page to be able to come up with a workable strategy between mixed teams.

Again, though, these are for open-water, direct-ascent dives in the 140-240 foot range. Not sure how it works in caves, as I haven't been there yet (four more weeks till I start finding that out ... )

... Bob (Grateful Diver)

 

[KMD]

Are you counting the deep stops as "deco"? Or is there 10mins of fudge in there?

At least for us, we usually communicated Tech1 dives in terms of max deco - since we were on one deco gas that was fairly straightforward. But for 2 gas dives its more along the lines of "max 190, 25mins BT" and we understand the consequences of that and 'convert' into obligations in our heads and say something like "my lp85s aren't quite full enough for that, we can try but I might be turning early on rock bottom."

No the deco time only refers to the time from 70 to 0'

To give a basic description:
150 for 25 = 150' feet for 25 minutes. This is the plan before we splash.
1:1 ratio = contingency planning on how our deco time will be adjusted one in the water based on our actual depth & bottom time
35 minutes max deco = The maximum amount of deco obligation we want to incur.

Note that this shorthand doesn't alleviate the need to run all the standard calculations for a tech dive (Minimum gas, Gas usage, Deco gas usage, CNS, OTUs etc...) With an experienced team on a relatively benign profile they have done before its just assumed that everybody has worked it out individually.

Your question on if I am counting deep stops as deco just proves my point though. Here we are two GUE trained Tech divers and even the simple nomenclature we use to describe a dive plan becomes open for interpretation. This is not because one of learned new material or "things changed between classes" but rather because our dive planning is shaped by our experience and environment.

In a lot of respect its the classic twins experiment. Take two divers and put them through a tech 1 class together. Then separate them geographically and have them do 50+ tech dives with new teams. There is going to be some drift in how they approach and plan things. Put them back together a year or two later and they might be on the same page anymore. It would behoove the diving twins to have a discussion on the important points before getting in the water.

As dives get deeper and more complex the need for detailed and discussed planning becomes greater and greater. As the team gains experience with the dives conducted some planning can be shortcut as it has been discussed and dealt with before, but when changing the dynamics of the dive (new team member, different exposure or site) the detailed planning needs to be there.

For example, If I am doing a three bottle dive, I will want to know what your expected bottom stage usage is. Why? because it gives me an indication on stress and planning during the dive. If we are planning to do 240' for 30 minutes and expect the stage to last 19 minutes and I see you switching off at 10 minutes, what does that say about our projected bottom time? Someones stress level? What their deco consumption will be?

 

[rjack321]

Your question on if I am counting deep stops as deco just proves my point though. Here we are two GUE trained Tech divers and even the simple nomenclature we use to describe a dive plan becomes open for interpretation.

Well this is why I said that its not really all that universal between agencies in the first place. Probably the worst example is the definition of "Tech2"

This is not because one of learned new material or "things changed between classes" but rather because our dive planning is shaped by our experience and environment.

Even within GUE the differences in 30/30 usage over time aren't trivial. The new "variable" ascent rate is another example. Within UTD the EAD of 25/25 is bouncing all over the place over time as well.

And then there are rumors and hints that CCRs are in agency futures (which I think is probably accurate to some degree), that would be a big shift from even an RB80.

 

[rjack321]

The group I do most of my tech dives with is a mix of GUE, UTD and NAUI-Tech. For the most part, it's like Kevin stated. We verbally walk through the dive plan and deco strategy and make an agreement on any divergences from the "standard" RD strategy. So far there's been only minor differences in how people want to approach deco ... mostly things like "let's spend an extra minute at 70 and 30" or "I'd like a couple extra minutes on the 20-foot stop" ... minor stuff like that. There's been almost no differences in terms of the length and depth of deep stops, shape of the profile, ratio setpoints, etc. Seems like everybody's close enough to the same page to be able to come up with a workable strategy between mixed teams.

I have heard of some interesting 50% profiles recently, with heavy emphasis on the <middle> stops for some reason. Like don't know the reasoning, but Kirk (or maybe it was Finley) dove out at Lk Crescent-Warren Car recently and was expected to run their deco this way. Not weighting either the O2 window nor the pressure gradient. Sounded weird to me, but I didn't get the whole story either.

 

[Bismark]

I have heard of some interesting 50% profiles recently, with heavy emphasis on the <middle> stops for some reason. Like don't know the reasoning, but Kirk (or maybe it was Finley) dove out at Lk Crescent-Warren Car recently and was expected to run their deco this way. Not weighting either the O2 window nor the pressure gradient. Sounded weird to me, but I didn't get the whole story either.

Kind of like making up your mind to firmly plant one foot on each side of the fence.......does seem strange. Maybe don't believe in the notion of 02 window but a bit afraid of the pressure gradient........;-)

 

[MXGratefulDiver]

I have heard of some interesting 50% profiles recently, with heavy emphasis on the <middle> stops for some reason. Like don't know the reasoning, but Kirk (or maybe it was Finley) dove out at Lk Crescent-Warren Car recently and was expected to run their deco this way. Not weighting either the O2 window nor the pressure gradient. Sounded weird to me, but I didn't get the whole story either.

Not sure I'm following how this applies to what I posted ...

... Bob (Grateful Diver)

 

[Sloth]

I have heard of some interesting 50% profiles recently, with heavy emphasis on the <middle> stops for some reason. Like don't know the reasoning, but Kirk (or maybe it was Finley) dove out at Lk Crescent-Warren Car recently and was expected to run their deco this way. Not weighting either the O2 window nor the pressure gradient. Sounded weird to me, but I didn't get the whole story either.

So it wasn't liner but it wasn't shaped to gradient or 02 window? How was it shaped? Sounds strange.

 

[rjack321]

Not sure I'm following how this applies to what I posted ...

... Bob (Grateful Diver)

Sorry, wasn't directly related. You move a min here vs. min there just made me think of it. The rumors I heard (really just rumors) some local folks are now shaping something like this:

10-2
20-3
30-4
40-7
50-4
60-3
70-2
= 25mins on 50% for a 15min dive on 21/35 to 170ft. No "o2 window" emphasis, no dissolved Buhlmann pressure gradient emphasis either. As I said, I wasn't there, I've just gotten things peicemeal and probably wrong too. But I thought it was interesting morph of the more typical RD rules. It probably works, just like most other shapes work, esp. for relatively short decos like this one. If anyone's been to Lake Crescent recently and cares to chime in and correct me I'm all ears.