Anyone using PDIS w/ Galileo Sol?

[scuba.dude]

My question isn't limited to Galileo if PDIS is available on other computers - just looking for feedback on PDIS. Tanks in advance.

 

[TheMadDane]

Ok, so the answer is yes, I'm using PDIS and now I need to know what your specific question is? What kind of feedback are you looking for?

 

[MMM]

Ditto

 

[scuba.dude]

Is PDIS valuable to a no-deco Nitrox diver?

I'm looking for practical value; e.g. when the HRM causes an 'increased workload' warning I simply mellow out and it extends my RBT - sometimes by 30% - so I wear the HRM on every dive. I read the PDIS manual - twice - and either I'm missing something or PDIS is really only valuable in conjunction w/ PMG for the deco crowd. Per the manual under no-stop diving (see sample1), if I'm at 77' I ascend to 42' for 2min when I've got an RBT of 3min. I'm doing a 35' ascent @ <30'/min plus a 2min PDIS stop w/ 3min left at depth - why?? Or (sample2) if I'm at 100' I ascend to 30' for 2min when I've got an RBT of 3min - this makes even less sense. If there's a mid-dive component (e.g. PDIS stop at dive time of 20min w/ RBT of 15min) is it the same crazy depth delta?? Again, practically speaking, if I'm on a wreck at 100', am I gonna take a 6min (2min up, 2min stop, 2min down) break to off-gas a little bit??

If you have thoughts/experience other than my question/s above, or I've made it painfully clear I simply misunderstand PDIS, please post that also.

Tanks,
scuba.dude

 

[scuba.dude]

apparently you can't upload images thru the Quick Reply feature ...

 

[TheMadDane]

I may have misunderstood the PDIS program feature but I was under the impression that it would give one more "Underwater" time not "Bottom time", if one was diving a gradually ascending profile?

Anyone?

 

[scuba.dude]

Interesting. Perhaps that is the casue of my quandary ...

I'll second Anyone?

In fact - Anyone? Anyone? Bueller? Bueller? Anyone?

 

[MMM]

I have used it only a few times (since getting a new 'puter on the warranty.). My manual is in Mexico but I don't recall the purpose having anything to do with extending either bottom or underwater. Rather it increases safety margin with off-gassing at deeper depths. And I believe it's useful for NDL divers - the manual takes you through how it operates when computer is both in deco and not. I did the stops a few times and missed them on others.

 

[Matt S.]

PDIS is a fancier deep stops algorithm. That's it. The difference, as I understand it from the manual, is that PDIS looks at your actual nitrogen load calculated from the dive profile. "Regular" deep stops instead use a simple algorithm like this:

A "Pyle stop" is an additional short deep-water stop, which is increasingly used in deep diving (named after Richard Pyle, an early advocate of deep stops[11]). Typically, a Pyle stop is 2 minutes long and at the depth where the pressure change halves on an ascent from the bottom to a shallow water decompression stop. For example, on an ascent from a maximum depth of 196 feet (60 metres) at 100 psi (7 bar) to a decompression stop at 65 feet (20 metres) at 40 psi (3 bar), the Pyle stop would take place at the halfway pressure, which is 70 psi (5 bar) at 130 feet (40 metres). [12] (Decompression stop - Wikipedia, the free encyclopedia)
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What is the practical benefit? Well, going up slower is always better, right? So I follow the Galileo's PDIS stop suggestions when I can. If it's not convenient, I don't worry about it.

Is PDIS better than Pyle stops? I can't say, but it certainly is easier to follow Galileo's suggestions than to calculate my own deep stops.

Note that I am not a deco diver, strictly recreational dive profiles for me. Most dives I don't get below 70 ft.

 

[scuba.dude]

MMM: thanks. Follow-up ques: are you diving PDIS w/ NDL or deco profiles? Also, are you using it deeper (than MattS) and if so, what do you like/dislike compared to your experience doing Pyle-type half stops?

MattS: great info!! Also, thanks for the practical application from real-world experience. BTW - cool avatar, where'd you find it?

MMM/MattS: I find the more 'stuff' I use the more alarms/warnings I get - do you guys just beep alot and ignore it, or turn off most of the alarms?