Question about learning deco procedures

[DanielRJones]

Yes. You must have a backup to whatever system you are using for your primary system. If you don;t use two computers, you need to have the written contingency plans and the instruments needed to use them.

Currently with a petrel 2 and a puck pro in guage mode. Will keep that for a while as it os the same conputer that my wife has 2 of so means that if i am diving o a liveabourd with the wife i use the petrel 2 but keep an eye on my puck pro so i roughtly know how long my wifes ndl is

 

[Edward3c]

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Many people diving in water with no hard bottom, such a following a wall, will go deeper than planned. (I believe that is because it is common not to add enough air to the wing to get perfectly buoyant when hitting the planned maximum depth.)
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I find most divers drop to their planned depth then correct for neutral buoyancy, which often results in exceeding their planned depth. I teach to stop at least 2m short, get buoyancy sorted, then go gradually to the planned depth (if it’s crucial to reach it).

 

[KenGordon]

I'm not downplaying the physical part by any means - I practiced stops on virtually every dive last month and even before that. I understand all these are not task loaded but coming up an anchor line is pretty easy, hanging from a surface marker isn't so bad but where I've really been focusing is trying to maintain with no reference, not looking at others but just staring into blue other than my computer - it takes a lot of focus to stay +/- 1' for up to five minutes, not terrible being +/- 2' but I really need to focus - it seems slightly easier at depth verses 15' but that may just be early thinking. I need to start adding tasks to increase the difficulty though.



Scubapro G2 supports gas switching, another task that I need to practice. It does not use GF but rather Micro bubble settings, the math is proprietary and won't follow V Planner or Mutideco from what I understand. It's great for the rec diving I currently do, easy to read and understand now that I know it, but I feel that I need to switch for planning purposes - it sucks that there transmitters are also proprietary.

I just started or logged into the training and won't start the class till week after next - there's a lot of good people on here that give answers with the reasoning behind them, and I greatly appreciate that.

Let's see in two weeks how much book smarts I have then we have to apply it in the real world..

thanks all!

The Scubapro site claims the G2 is ZHL16 with some adaptive stuff. Chances are you will be able to produce a plan with MultiDeco which will do.

 

[boulderjohn]

I find most divers drop to their planned depth then correct for neutral buoyancy, which often results in exceeding their planned depth. I teach to stop at least 2m short, get buoyancy sorted, then go gradually to the planned depth (if it’s crucial to reach it).

As do i. But then I notice that as they swim along, theoretically staying at the planned depth, the tendency is to drift down, correct, drift down, correct, etc.

 

[ChuckP]

The Scubapro site claims the G2 is ZHL16 with some adaptive stuff. Chances are you will be able to produce a plan with MultiDeco which will do.

Well.... I just hit the order button on a Shearwater - oh well, just another thing my ex can't get.....

I've been curious to dive them side by side anyways. It doesn't mean a whole lot to me but during a class using the compass, sorry but the G2 one really had issues as compared to my instructors Shearwater.

At my age, my reading vision isn't the best either, my mask is prescription but there's some little words on the G2 that aren't the easiest to read, we'll see how this other one looks underwater.

 

[scubadada]

The Scubapro site claims the G2 is ZHL16 with some adaptive stuff. Chances are you will be able to produce a plan with MultiDeco which will do.

I don't think so, the "adjusted" algorithm is quite conservative

 

[ChuckP]

Another thing about the Scupapro stuff, you can have a heart rate monitor connected that factors that into the whole equation - curious to see them side by side.

One downside, the Scubapro does not log NDL time, not sure about Shearwater - not sure how else you could compare conservatism.

 

[boulderjohn]

Another thing about the Scupapro stuff, you can have a heart rate monitor connected that factors that into the whole equation - curious to see them side by side.
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See if you can figure out what the computer does with the information from that heart monitor. If a very fit diver whose resting heart rate is normally in the low 40s works hard enough during a dive to get the blood flowing enough to affect ongassing or offgassing, it might go all the way up to 55-60 BPM. Another person resting calmly during the dive might be at his or her base rate of 75 BPM.

What algorithm do they use to translate that information into action?

 

[ChuckP]

See if you can figure out what the computer does with the information from that heart monitor. If a very fit diver whose resting heart rate is normally in the low 40s works hard enough during a dive to get the blood flowing enough to affect ongassing or offgassing, it might go all the way up to 55-60 BPM. Another person resting calmly during the dive might be at his or her base rate of 75 BPM.

What algorithm do they use to translate that information into action?

5 Workload: At the base of any decompression calculation there is the transport of nitrogen from the lungs to the blood and from there to the tissues during on-gassing, and the same but in reverse during off-gassing. As such, it is obvious that the single most important parameter in a decompression calculation is the rate at which blood travels through the body. During heavy exercise, the total blood flow from the heart can be up to 4 times higher than while at rest. This increase in blood flow is rather unevenly distributed, with some tissues such as the Central Nervous System and the brain being unaffected, while others like the muscles receiving up to 10 times more blood than when at rest. The G2 estimates workload based on heart rate or changes in breathing pattern from the high-pressure transmitter, and the decompression calculation in the ZH-L16 ADT model is changed accordingly. This menu allows you to select the workload base or switch off the workload estimation, in which case your G2 will behave like SCUBAPRO dive computer models without heart rate or air integration. SCUBAPRO recommends using the workload and Heart Rate features on all dives, but especially when making technical dives. When the dive goes as planned there is no effect to the decompression schedule. However, when workload is high more decompression time will be required. Adaptive algorithm additionally incorporates into the calculation the water temperature or skin temperature (only with the patented SCUBAPRO Heart Rate belt) and micro bubble formation.

That's what it says in the manual - when the monitor works, it records the HR and you can see it in graphs - but it's sketchy at best IMO. I don't know if it chews thru batteries or just loses connection - it'll work on the boat but at times below 20' it just stops and I ain't dead.....

Back at the beginning for me, being older and not some triathlete, I liked the idea of being able to see my HR and how depth, descents etc effected it, I thought it helping keep me safe was real important too.....

 

[ChuckP]

It all makes sense what it's doing from what I've learned, recreationally it really makes sense, but what and how, I don't know.