DIR- GUE Why are non-GUE divers so interested in what GUE does?

[Adobo]

When I was shooting a fully manual medium format camera using a spot meter, I was shooting often enough that after doing a reading, I was telling my meter "yeah, that sounds about right." Some photographers would stop using a meter as they could "see" the exposure. I wouldn't recommend that for a deco schedule, but getting to the point of knowing what the computer will say before looking is an indication of knowing a dive profile quite well.

Ratio exposure.

 

[PfcAJ]

My understanding is that Ratio is a more formalized method to those patterns that you notice that way. And I certainly notice those patterns, I can tell you about how much deco I am going to have in a dive just by looking at the average depth, and how much gas I am planning to bring with me.



I think you might misunderstand me. First I am not an OW tech diver, I do that occasionally but a vast majority of my diving is in caves. And I don't do it for the thrill, but because I enjoy what I see. So my dive plans are fairly conservative and involve work up dives. When I take DPV Cave later this year, you aren't going to see me slapping on two scooters and running out to Well Casing or Henkel (for non-cave divers these are major check box destinations far in their respective caves). I'll be using them to take me to the edge of the cave I know well, and then work my way up past there. I view deco the same way, and TBH I am a bit of a coward.

My dislike for Ratio is that I don't believe that I should be doing math like that underwater. And that it would take so many prior failures for me to even consider going down that path. And I question the value of having students learn a system with little utility. But I consider it a minor issue and more class related items that are retained even when their utility has become minimal, sort of like buddy breathing that is still in TDI deco classes.

For the dives you’re describing, RD doesn’t really give you a whole lot.

For something deeper though, say… Eagles Nest downstream, it does. It’s like a 4 or 5:1 ratio (your deco gases and gradient factors really start to show) for something like that.

Maybe you wanna go swim to see somethin 5mins farther in. That’s 10mins more on the bottom.

You just bought nearly an HOUR of extra dive time.

Now I know this is a fairly extreme example, but it goes to show how identifying trends can help you make informed choices on the dive. Do you have the resources to sign up for that? Thermal? Nutrition? Gas? Lights? What about in the ocean? Weather, the boat’s expectation, currents, amount of drift, Sun position change. All matters.

Places like Ginnie or LR are shallow enough that it’s real tough to get yourself into a situation that results in more than 20mins or so of oxygen deco. Somewhere deeper? Boi you better be on it cuz it can get away from you.

 

[Adobo]

Thanks. Glad you're so open to other techniques and methodologies.

I took a hiatus from diving for a few years. When I started diving again, I needed a new computer. <- has to do with a family member who is diving now also.

I came to the DIR forum to ask what the computers they recommended - something that does gauge mode and logs dives and so on. Just basic stuff.

Come to find out that these folks are now using computers in conjunction with their tables/dive plans. Its probably been this way for a while now.

 

[Manatee Diver]

For something deeper though, say… Eagles Nest downstream, it does. It’s like a 4 or 5:1 ratio (your deco gases and gradient factors really start to show) for something like that.

Maybe you wanna go swim to see somethin 5mins farther in. That’s 10mins more on the bottom.

You just bought nearly an HOUR of extra dive time.

On my computer I use Delta 5 (which I keep on my main screen) for that purpose underwater.

Now I know this is a fairly extreme example, but it goes to show how identifying trends can help you make informed choices on the dive. Do you have the resources to sign up for that? Thermal? Nutrition? Gas? Lights? What about in the ocean? Weather, the boat’s expectation, currents, amount of drift, Sun position change. All matters.

Now if it is mostly used above water as a rule of thumb, I have less issue with it. In fact I mentioned I use the rule of 130 all the time to see if I need to pull out Multideco or not, but I would never use it underwater.

But like I said fairly minor issue that wouldn't stop me from taking the class.

 

[RedSix]

Thanks. Glad you're so open to other techniques and methodologies.

What's new about using a computer?

 

[Wibble]

What's new about using a computer?

Reliability. Decent user interfaces. Rebreather integration. Using gradient factors. Discipline to ensure it’s correctly configured before jumping in.

 

[kensuf]

And my issue with it is that if both my computers fail, I have no way to knowing what my current depth or time is; and thus have switched to emergency plans like using my buddy's computer. Which I can follow that profile, if all the computers have failed you are in deep sh*t, and you go with whatever cut plans you have and hope that you can count time accurately in your head.

Where's the 30' stop in Ginnie? How about the 20' stop in Ginnie? (The grim reaper sign, the floor of the eye).

Where's the 30' stop in Little River? How about the 20' stop in Little River? (The big boulder, the lip by the spike).

You don't need a depth gauge to know where you're doing deco in a cave. Timing device? Hells ya, but depth gauge, no. For cave diving I bring a watch and a single computer, look at the time before I descend, it's that easy peasy. If you're losing both timing devices then I'd say that's a surface problem.

Ocean? Yes, bring a redundant depth gauge.

 

[kensuf]

I'm not sure what part you disagree with the tech1-v4.0 basically says not to use it as a primary means and includes procedures for using computers and deco planner as well

As far as knowing current depth, your SMB tells you that, and some might call me old school but there's a reason I always wear a dive watch.

SMB's don't accurately tell you your depth when you're hanging in a multi-level current and the line is being pulled at a 45° angle.

 

[Wibble]

SMB's don't accurately tell you your depth when you're hanging in a multi-level current and the line is being pulled at a 45° angle.

But you don't hang on it; you let it bounce up and down in front of you. A good reason to use a substantial reel. But if using a lightweight spool, hang some double enders on it and adjust the length according to your depth indicating device (a capillary tube?). Then use that as a guide depth.

(A big reel will laugh at the current and bounce up and down nicely)

RHW 100 Metre Line Narrow Composite Ratchet Reel + 25mm Single Handle

www.divingproducts.co.uk

 

[kensuf]

But you don't hang on it; you let it bounce up and down in front of you. A good reason to use a substantial reel. But if using a lightweight spool, hang some double enders on it and adjust the length according to your depth indicating device (a capillary tube?). Then use that as a guide depth.

(A big reel will laugh at the current and bounce up and down nicely)

RHW 100 Metre Line Narrow Composite Ratchet Reel + 25mm Single Handle

www.divingproducts.co.uk

Hang means "floating for deco", ex. "I drifted 5 miles during that 30 minute hang in the Gulf Stream current last summer."

In a multi-level current, if you let an SMB just "bounce up and down in front of you" you will never see it again. We've got places here where you can have a 2-4kt current at one stop depth and nada at a deeper one. Heck, it's really exciting when surface currents are going one direction and bottom currents are going the other.