Tech computer: Perdix or Petrel 2?

[boulderjohn]

hat are your thoughts on AI as a tech diver? Now that I have decided on the Perdix, there is still the matter of buying the standalone or the AI version. I would probably never use it as a feature but could it potentially be useful?

There have been discussions about this in the past, but the thinking on this issue is fast evolving. I would bet the responses a new discussion would inspire would be surprisingly different from discussions in the past. I strongly suggest that rather than tack this question on at the end of a thread that has pretty much run its course, create a new thread with this new question.

 

[Caveman]

There have been discussions about this in the past, but the thinking on this issue is fast evolving. I would bet the responses a new discussion would inspire would be surprisingly different from discussions in the past. I strongly suggest that rather than tack this question on at the end of a thread that has pretty much run its course, create a new thread with this new question.

Good idea. I shall do so. Thanks John

 

[TrimixToo]

Indeed. And a very useful breakdown of the features of each. The Perdix just seems to be the better computer. And for costing the same price, there's no question. What are your thoughts on AI as a tech diver? Now that I have decided on the Perdix, there is still the matter of buying the standalone or the AI version. I would probably never use it as a feature but could it potentially be useful?

And with regards to a second computer, could I use my rec computer (Cressi Giotto) or were you talking about rec computers being a bad idea and it would be best to own two Shearwater computers; one as the primary and the other as a back up.

You can use a rec computer as backup as a bottom timer, with tables cut for the dive, including plus (more time and/or depth) and minus (less) tables. Most people, me included, start that way, because of the cost. But decent used tech computers of some description with reasonable algorithms are not expensive (I bet you can find a VR3 for fifty to a hundred bucks if you look around, and it's a fine computer even if it is complex to learn--and it is!--and if it does eat batteries--and it does!).

It would be best to have two tech computers. That's two that know what you are breathing, and two you can rely on without sorting through tables. When TSHTF, if your one tech computer fails, the complexity of the dive will take a sudden, big uptick when you need it least, and the time it takes to get out of the water *will* be longer. RD is another backup strategy, and a good tool to have in one's belt as well, in my opinion. (Please, please, let's not restart the RD debate off this thread.) I would prefer that my computers not be identical, but others will probably not care, and in many areas of human endeavor--including tech diving--there is more than one "right" answer. I am very happy diving two different Shearwaters, but others are doubtless just as informed as I am (or more) and perfectly happy with to identical Shearwaters. There are ups and downs to both solutions (for example, my Petrel and my Perdix are not identical in operation).

Here is something you did not ask about but I will add anyway. When you venture into tech, advice becomes yet another form of imperfect information you have to weigh against what you think you know, and that you can use to inform your decisions about risk management. Boulders of salt are required to be dispensed with much of it, including any I might happen to offer. So think about what I say, and what others say, very carefully and decide for yourself what diving contracts you are willing to sign. What do those terms and conditions say you will have to manage or accept when "X" happens?

 

[Caveman]

Here is something you did not ask about but I will add anyway. When you venture into tech, advice becomes yet another form of imperfect information you have to weigh against what you think you know, and that you can use to inform your decisions about risk management. Boulders of salt are required to be dispensed with much of it, including any I might happen to offer. So think about what I say, and what others say, very carefully and decide for yourself what diving contracts you are willing to sign. What do those terms and conditions say you will have to manage or accept when "X" happens?

Same as when I started with rec 2 years ago, so much advice and so many opinions. I have often tried to best to simply use them as guidelines to then personally make an informed decision. Recently the difficulty has been in buying new gear; as you mentioned previously, deep diving requires deep pockets. Much of the gear can be rented but in the immediate future it is important for a tech computer and it would appear that the opinions of Shearwater computers being the best are almost unanimous. Later on down the line I'll likely buy a Teric or a Petrel if they are still making them by that point for the sake of not confusing the two computers. But in the mean time, still recently new to tech diving and also venturing into caving before I start my Trimix training, one computer will do for now I am thinking, using my Cressi as a backup until I organize a 2nd Shearwater

 

[tbone1004]

Overall, I like the Perdix better, mostly because it doesn't catch on as many things and because I like its gas switch menu better, but they are otherwise so close to the same that it's hard to differentiate them.

Even with old software, you should be able to set the Petrel to the "new" style gas switch in the settings...

@Chase Kaplan The Cressi should be fine for now, just learn the conservatism settings on it and how they correlate so you don't piss it off too much

 

[boulderjohn]

Even with old software, you should be able to set the Petrel to the "new" style gas switch in the settings...

Yes. The software is identical. If you like the gas switch settings on the Perdix, then by all means set it up that way on the Petrel.

 

[TrimixToo]

As I posted before, the software is not identical. The Perdix is current; the Petrel is on V38. I'll try to remember to notice what's different tomorrow. It's not much; I just find the Perdix one more readable. I cannot, at the moment, recall just why.

 

[tbone1004]

As I posted before, the software is not identical. The Perdix is current; the Petrel is on V38. I'll try to remember to notice what's different tomorrow. It's not much; I just find the Perdix one more readable. I cannot, at the moment, recall just why.

on v38 it certainly has the same gas switching options as the Perdix but IIRC the Petrel defaults to the "old style" of gas switching. Super easy to change in the menu's.

 

[boulderjohn]

As I posted before, the software is not identical. The Perdix is current; the Petrel is on V38. I'll try to remember to notice what's different tomorrow. It's not much; I just find the Perdix one more readable. I cannot, at the moment, recall just why.

I have the Petrel (not Petrel II) and the Perdix. The gas switching is identical in each. When I tell them I want to change gases, they both show me all the gases at once, with the one I am most likely to select ready to go. The figures are too small to see easily with my aging eyes, but if I just click to accept whatever is selected, I will then see it in the nice big numbers on the main screen.

 

[TrimixToo]

I have the Petrel (not Petrel II) and the Perdix. The gas switching is identical in each. When I tell them I want to change gases, they both show me all the gases at once, with the one I am most likely to select ready to go. The figures are too small to see easily with my aging eyes, but if I just click to accept whatever is selected, I will then see it in the nice big numbers on the main screen.

The operation is identical. I recall the the display is not. But I will try to remember to check tomorrow.