Shearwater Perdix Air Integrated...Opinions

[scubadada]

Synchronization problems, signal loss, not robust enough...?

I've been diving an AI Oceanic VT3 since July 2010 with in excess of 800 dives. The transmitter is permanently synched with the computer by the transmitter serial number. I have never lost signal for more than 30 seconds. All signal losses are displayed on the dive graphic when you download to your computer. I'm on my 4th set of batteries, I get 250-300 hours per set. I change batteries as soon as the computer display gives me a low battery warning. It is very easy to check the transmitter battery, I have never has a transmitter low battery warning but always change it at the same time as the computer battery. By the way, Shearwater is using the same Pelagic Pressure Systems transmitter that I have been using for the last six years.

Mental laziness...?

Well, maybe this one is true. I want to see my RMV, why, because I like it. That's a good enough reason for me. I'm not interested in recording my start and end pressures and doing the calculation. My SAC and RMV are calculated for me on download. I don't actively use the ATR calculation, though I do look at it occasionally. After 1200 dives with Oceanic AI (ProPlus and ProPlus2 before my VT3), I happen to know the Oceanic iteration of ATR is quite accurate, both for NDL diving with a SS or with my light deco.

So the tech divers have the Petrel and the Perdix and don't have to be bothered by the useless, failure prone AI. If my VT3 ever fails, I'll get myself a Perdix AI, or some other quality AI computer that may be available by then. Something for everyone

 

[geoff w]

I spent some time talking to the Shearwater guys at DEMA last week. The push for wireless was for the sidemount community, to make it easier to see the pressure in both tanks (I don't dive sidemount, so won't speculate on why it's useful). They designed it with the highest quality antenna available, so should have fewer pairing and sync problems compared to most other WAI dive computers. They've obviously tested it enough to the point where they are confident in releasing it as a product with their name on it.

If you have compatible wireless transmitters, you can just reuse those instead of buying more. Wireless makes sucks about 5% of the battery life. I never really paid much attention to the Perdix before, but it really is a lot more compact than my Petrel 2. I didn't ask if it calculates remaining bottom time based on gas consumption and pressure (didn't ask), but got the impression it really just displays pressure for two tanks. Check with Shearwater for definitive answers

 

[lowviz]

...//... No problem, if you just want to go diving without the mental burden, go ahead. Enjoy your dive, but please do not to attempt to do more demanding dives ...

My "big" dives are nothing more than light deco but I still take them seriously. On most of my just plain fun dives, I can't get deep enough to EVER go into deco. On "big" dives, I'm hyper-aware of the nuts and bolts. On "fun" dives, I like reminders.

To be honest to me it looks like they've added pure recreational functionality (AI) to a very good technical diving computer. ...

You say that like it is a bad thing...

...//... If on the other hand, you are planning on staying as a serious rec diver, and you like AI, then go for it.

Stoo totally gets it.

If you like post analysis as an integral part of the dive then there's no other option than AI. Totally agree on this. ...//...

Thanks.

My potential interest in AI is for both diving doubles and post-analysis. Doubles: @Shearwater, Just show me the average pressure of my two tanks in green. That value goes yellow when it is time to switch. Make it a user-selectable differential in pressure.

Post-analysis: I know my SAC. But that single value is an average over a lot of very different dives. I love gas planning, I want to know my SAC when cold at the end of a dive, when I'm vegging out, when I'm uncertain with what is happening... @Kevrumbo, we have agreed/tangled in many past posts and threads. I find it refreshing, you keep the Luddites alive and well. (Intended mild sarcasm aside), there is value in what you do. Quite often, there exists a simple answer to what a "data nerd" is blind to either seeing or understanding. For most of my diving, if I "F-up", I just ascend to 20' and suck down everything that I brought with me. Show me where that is wrong in an over-tasked, mental lock-up scenario.

...//... It only seems like a "mental burden" as @lowviz and others claim because just like learning anything new & unfamiliar, it takes time to read, comprehend and accommodate the process versus actually practicing it.

Might as well discard the WAI and keep the reliable practical SPG then, applying what you learned about gas consumption & management in the first place and should've been proficient in doing all along. . .

I know that you are aware that I am capable of doing the calcs if need be. I don't dive the way that you do, never will. I can do a lot with pencil and paper. But I now prefer a calculator. When the first four function calculators came out, I would quickly check the result with a slide rule or pencil and paper. We learn to let go and move on...

...//... because just like learning anything new & unfamiliar, ...

After 38 years in research support, I'm OK with the world of new and unfamiliar. I am also amused by the use of misrepresentation: What controversy: Is a controversy misrepresented or blown out of proportion?

I dive to decompress, Kev. When I can't dive, I love to discuss diving.

 

[Kevrumbo]

My "big" dives are nothing more than light deco but I still take them seriously. On most of my just plain fun dives, I can't get deep enough to EVER go into deco. On "big" dives, I'm hyper-aware of the nuts and bolts. On "fun" dives, I like reminders..

Post-analysis: I know my SAC. But that single value is an average over a lot of very different dives. I love gas planning, I want to know my SAC when cold at the end of a dive, when I'm vegging out, when I'm uncertain with what is happening... @Kevrumbo, we have agreed/tangled in many past posts and threads. I find it refreshing, you keep the Luddites alive and well. (Intended mild sarcasm aside), there is value in what you do. Quite often, there exists a simple answer to that a "data nerd" is blind to either seeing or understanding. For most of my diving, if I "F-up", I just ascend to 20' and suck down everything that I brought with me. Show me where that is wrong in an over-tasked, mental lock-up scenario.

I know that you are aware that I am capable of doing the calcs if need be. I don't dive the way that you do, never will. I can do a lot with pencil and paper. But I now prefer a calculator. When the first four function calculators came out, I would quickly check the result with a slide rule or pencil and paper. We learn to let go and move on...

After 38 years in research support, I'm OK with the world of new and unfamiliar. I am also amused by the use of misrepresentation: What controversy: Is a controversy misrepresented or blown out of proportion?

I dive to decompress, Kev. When I can't dive, I love to discuss diving.

Lowviz -Do you need a calculator to figure out how much change you're getting back during a cash register purchase!? Of course not!

Can you do iterative subtraction from a starting gas pressure in your dives without an AI? Sure! But you prefer having AI for the post-dive data logging feature (correct?):

So show us here in the Tech forum what you've learned & applied to & about your dives (Sac Rate, starting & ending pressures etc) that you find an AI function to be so indispensable. . .

 

[lowviz]

...//... So show us here in the Tech forum what you've learned & applied to & about your dives (Sac Rate, starting & ending pressures etc) that you find an AI function to be so indispensable. . .

You speak directly to the problem whether you know it or not. The Tech forum is beginning to rot around the edges. You can thank the agencies for that. Haven't you heard, AOW is the new tech. You won't see me on RBW, CDF, or DS. I don't belong there and I know my place.

Why are you here?

 

[DevonDiver]

Working out maths questions is just as evidential of 'internet diving' as it is of advanced/technical diving.

Preoccupation with such foundational tech matters might be very evidential of internet diving....

Here in the Tech forum we should assume that debate participants all have these most basic competencies down to par.

"Helping learn my gas consumption", should be the type of opinion preserved for AI threads in the Basic Scuba area of Scubaboard...

Issues like; "improving or sustaining situational awareness under high stress conditions" are much more pertinent to the tech AI debate.

 

[lowviz]

You want to label me as an internet diver? Fine. Do so. I am. Now what? 80% of what I've found to be true IRL came not from formal courses, but the net. I dive, you can't stop me.

...//... "improving or sustaining situational awareness under high stress conditions" are much more pertinent to the tech AI debate.

This is my shortcoming and I will admit it. Been there and came back with a broken ear. (Non-AI but highly related) Lesson learned. Check that box, move on.

How does one practice under high stress conditions? Been there several times IRL, it is a bitch. I've become penicillin intolerant due to my last episode. You guys are the gods, just like boat captains. You all talk. I just dive and try to get better at it.

You can't stop me, would be nice if you tried to help, though.

 

[Ayisha]

Apparently Canadians use PSI too. The two I had (well, technically they were German and American but had lived in Victoria for 10 years) in a fundamentals class couldn't explain how it worked out that way, but that was how it was.

Yes, Canadians generally use metric in regard to everything except scuba. I was told years ago that it was because our tanks (cf), gauges (psi), hoses (feet, inches) etc. predominantly come that way from the U.S. Canada switched from the imperial to the metric system in 1970, but the schools didn't start teaching metric until the mid-to-late 70's, so people over 40 are well versed in imperial and metric.

Shearwater is a great Canadian company that makes excellent computers, but I'm not sure the WAI is there yet either. The size and location of the transmitter as well as to a lesser extent, the smallish risk of loss of transmission are points of concern for me. I started with analog gauges, was very happy with a console AI for over a decade, then went back to an analog gauge (plus wrist computer) a few years ago. I check my air consumption often, mainly to confirm it's where I expect it to be, and don't miss the AI at all.

I believe Shearwater put out a statement about retrofits being available next year, so there's hope for your new Perdix if you choose to convert.

 

[DevonDiver]

You want to label me as an internet diver?

Wasn't aimed at you buddy. Was a generic point.

 

[DevonDiver]

Can you input tank capacities into the computer?

If so, would the shearwater compare available gas versus predicted deco?

If deco > gas.... would, or could, the shearwater calculate a best option deco based on insufficient gas?