Cobra vs Vyper: Air Integration or Not

[Beatlejuice]

I'm a newly certified diver cautiously shopping for my first equipment. I've pretty much narrowed down my computer selection to the Cobra or Vyper, the difference between the two (as far as I can tell anyway) is that the Vyper has air integration (and therefore connected to the HP hose) and the Cobra does not. I like the idea of the computer being able to track my air usage, but I can't seem to shake the feeling that I would prefer to have an mechanical SPG (something that's not susceptible to electrical malfunction). Am I being paranoid? Is it possible to have the Vyper and an SPG attached to the hose at the same time, maybe even built into the same console? Is the air integration really that useful? (I'll leave the discussion of the "2" models, compass & nitrox functions, for another thread!) Any thoughts, opinions and advice would be greatly appreciated! Thanks!

 

[TSandM]

I believe the Cobra and Vyper are both air integrated (I know the Cobra is) by direct connection to the HP hose (they're console computers). The Vytec is the wrist-mounted version of the Vyper, with an electronic transmitter to send the pressure information to the computer.

I like a wrist-mounted computer, because I can glance at my wrist and check my depth and dive time very easily, without having to pull anything up to look at it. My pressure is measured by an analog gauge, and I only need to check that at intervals, so that works for me.

Giving up air integration makes the gauges much less expensive, too, unless you have champagne tastes.

 

[kadleck]

Vyper is not air integrated (it is wrist mounted - at least mine is ). It is good practice (especially with the radio transmitter types of air integration) to have an analogue SPG as backup.

FWIW, If I were the OP, I would go with Vyper (I have Vyper) and an analogue SPG.

 

[avenger]

Okey so to make it short....

The Cobra and Cobra2 are your all-in-one console computers and have the direct connection to the to the HP hose. Vyper and Vyper2 are wrist-mounted computers while Vyper2 can also be mounted in to your console. Only wrist models that have the AI are the D9, D6 and Vytec DS. You can check the individual differences by comparing the models at Suunto´s website.

In your case I would first decide between a wrist-mounted model and a console. Many people atleast here in Finland prefer analog SPGs and DGs as a backup while diving with a wrist computer. Some have even 2 computers. Atleast for me it is a lot easier and natural to glance my wrist should I ever need any information. And in the unlikely event when your computer fails, you would still know how much air you have left and what is your depth since you have the analog gauges as a backup.

Most people that I know of think that the AI is way too expensive, which is true. But still it has some "nice" features, and I say "nice" because the usefulness can be argued. If you think that the seeing your remaining air from your computer is worth the price, get it. Otherwise don´t. The only reason I have the AI is that I got it so cheap with other stuff that it didn´t even matter. I haven´t tried it though since I just got it but I´m testing it next weekend. I would say that the AI is not that "useful" but it is certainly a nice thing to have.

It is not paranoia and you can definetly have the AI and an analog SPG at the same time. That´s exactly what I have. And if money is not the issue, get the Vytec DS with the AI. Otherwise I would get the model that suits best your needs. Vypers are good and have all the essential features. And as long as the AI transmitter, Vytec DS and Vypers at least here in Finland cost the same, I would think twice whether I need it or not. There are like a million better ways to spend the money

 

[ClayJar]

Is it possible to have the [Cobra] and an SPG attached to the hose at the same time, maybe even built into the same console? Is the air integration really that useful?

In order to use a Cobra and a mechanical SPG at the same time, you'll need two HP hoses. (The wireless air integration transmitters attach directly to your first stage, so those don't need their own hose.) If your first stage has only one HP port, it is possible to [thread=210571]buy a "splitter"[/thread] to turn that one port into two for the purposes of attaching an SPG and air integration device (wireless or a hose to the Cobra), but I know of no similar device for the instrument end of the HP hose, and if could procure one, you would not be able to fit everything in one console, anyway.

From what I've been told the Cobra only logs your starting and ending pressures. (I do not have one to verify, but several posters here have agreed with that statement.) That saves you from having to write the pressures down on a slate or something, but how useful is that in practice? (Although it's somewhat off-topic, let me note that I have been told by Cobra2 owners that the Cobra2 logs more pressure information that just starting and ending pressures. That may make it more useful in my mind, but that's neither here nor there for this thread.)

As far as during the dive goes, what does air integration get you? Honestly, not much. Obviously, it shows you your pressure, but it takes more mental effort to read digits than to comprehend a simple dial gauge. (The human brain interprets shapes more directly than numbers, I suppose you could say. It's a fascinating area to read about, if you're ever bored.)

You also get an "estimated time to depletion" number, but the problem with that is that the computer can neither measure your current state nor predict the future. The computer can tell you how quickly you're currently using your air, but that's it. It doesn't know your dive plan. (Do you care that your air would last another 17 minutes here at 81 feet, when you're about to ascend to the deck at 65 feet to continue your dive?) It doesn't know whether there's something that may increase your air consumption. (If there was a strong current all the way down the line from the boat, you'll know to save a bit more for the way back up, but your computer won't.)

I certainly won't say that air integration is a bad thing. It's just an interesting bit of trivia, and you may enjoy it. Personally, I did not consider it to be worth the expense, and I wanted my plain jane SPG. What I did, instead, was to work out air consumption numbers for my standard ascents. I made a little (business card size) table of depth and absolute minimum pressure, laminated it, and zip-tied it to my SPG. Then I just had to look at my depth gauge and glance at the chart to see how much longer (in pressure) I could stay there. (I don't use the chart much anymore, as it's all in my head now.)

When I'm diving, I don't convert between pressure to time. I have my NDLs on my computers, so I know how many more minutes I can be there. Then I have my pressure on my SPG, so I know how many more PSI I can be there. Whichever makes it to (well, near) the limit first wins, but I see no need to figure out how many minutes a certain pressure is. (Obviously, I have a rough idea, but there really isn't much point for trying to get a very precise number, as your consumption rate will necessarily vary enough that anything but a rough approximation would be nothing but false precision.)


(Oh, and for the record, the Gekko, Vyper, Vyper2, and Vytec are all the same size, shape, et cetera. You can use any one of them on your wrist, in a console, or in a DSS bungeed wrist boot. The D-series, Mosquito, and such are watch-style and cannot be put in a console. The Cobra and Cobra2 are console-only.)

 

[Beatlejuice]

Wow great feedback! I'm pretty sure that I want a console as opposed to a wrist mount, although I'm not closed off to the idea. What I've found interesting about the integrated air is being able to track my air useage as a way of improving my breathing underwater. So far, the more I'm reading hear, the more I'm leaning towards the non-integrated.

Thanks for all the input. Anyone else?!

 

[ClayJar]

I'm pretty sure that I want a console as opposed to a wrist mount, although I'm not closed off to the idea.

The nice thing about the Gekko/Vyper/Vytec family is that you can go console, and if you later change your mind, it's trivial to go to a wrist mount. (You have to be able to use a phillips screwdriver, and if you go with a DSS bungee mount, you have to be able to tie a knot. ) Of course, you can also go the other way (a *few* people have) -- you'd just order the console boot and get your phillips screwdriver back out.

What I've found interesting about the integrated air is being able to track my air usage as a way of improving my breathing underwater.

Danger, Will Robinson! Danger!

Tracking your air usage is a way to *observe* your diving, but watching your air usage as a way to *improve* your diving is one of the best ways to create problems.

There are very few problems in diving that are *caused by* how you're breathing. Barotrauma caused by holding your breath is the obvious one. Then there's the whole CO₂-related set, which can be precipitated by shallow breathing, skip breathing, hyperventilating, trying to breathe "right", and so on. Breathing is *not*, however, the cause of high air consumption.

Put simply, your body knows about breathing. It's been doing it without your conscious help practically all your life. Your body uses breathing as a way to acquire oxygen, obviously, but more significantly, it uses breathing as a way to get rid of carbon dioxide. The more carbon dioxide your body is creating, the more breathing it does to get rid of it. The amount of oxygen is almost always a moot point. (If you were doing wind sprints in a gym full of pure oxygen, you'd still be breathing just as hard... although you'd better not be smoking. :biggrin

Anyway, so what does this mean for diving? How much you're breathing is related to how much CO₂ you're creating. How much CO₂ you create is based on how hard you're working (swimming against a current will burn more calories, creating more CO₂), how warm you are (if you're in a shorty in cool water, you'll be burning more calories just to try to keep warm, creating more CO₂), and how you're feeling (the less stressed you are, the less CO₂ you're creating -- when you think "Is it getting hot in here?", that's because you're going through the calories).

It's easy to handle the warmth part. If you're shivering, you're flying through air. The warmer you are (without overheating, which would be *bad*... not to mention uncomfortable), the less CO₂ you'll make just to keep warm.

How you're feeling is pretty easy too. If you're worrying over your air consumption, you're making it worse. :biggrin: Don't push your comfort zone too far, and just accept that what your air consumption is, it is.

How hard you're working, however... *That's* the kicker. If you're not in horizontal trim, you're doing possibly *far* more work than you need to be. (If you're upright or even inclined, you're swimming up with each kick. To stay at the same level, you then have to be negatively buoyant. You're basically holding a weight up the entire dive! If you start sinking when you stop kicking, you're wasting air and doing lots of extra work.) If you're racing around, slow down and look at the little things. (You can spend an entire dive within the area of a backyard pool and see all sorts of amazing things, or you can speed around the dive site and see a couple cool bits while you burn right through your air.) If you're horizontal and looking at the details, your air consumption is going to be vastly superior to what it would be racing around on an incline.

(When I got horizontal by moving four pounds from my waist to the shoulder of my tank, my air consumption improved by a full 25% in the space of a single dive. That improvement remained from that point on, although over many dives, I gradually improved on even that.)

The key is that you can look at air consumption (i.e. breathing) to tell you how your diving is going, but if you want to improve your air consumption, you can't do it by changing your breathing. You have to change your diving. I've never tried to change my air consumption, but I have certainly let my air consumption point out things in my diving that could use some attention.

 

[reefduffer]

I have a Cobra and like it.

If you're happy with a console, as I am, and you indicate you are, then you get AI without all the transmitter baggage - expense and failure potential. It's still neither as inexpensive, or probably as reliable, as a mechanical SPG, but it's suitable in both respects for my use as a recreational diver with a moderate gear expense budget.

I like having it record starting and ending pressures so I can calculate SAC. As others have said, you could write that on a slate or remember it, but somehow there's sometimes too much other stuff happening at entry and exit and it gets forgotten. Problem solved.

I like it estimating my remaining air time, even if I know that's an estimate.
I like having only one thing to look at that has all of the time/depth/air info in one place.

I keep it on a retractor at mid-sternum. In my normal stable diving position on daylight dives I don't need to move anything to look at it, just glance down. Almost as good as a HUD.

It won't be the best solution for other types of diving or other tastes or other budgets, but it works for me.

 

[LowVizWiz]

From what I've been told the Cobra only logs your starting and ending pressures. (I do not have one to verify, but several posters here have agreed with that statement.)

The Cobra does record your usage during the dive the problem is that SDM software does not show you that info. It only gives you starting pressure and ending pressure and an a linear graph between the 2 points. If you use a different software to extract the info from the computer you will see actual air usage during the dive.
This is one dive from a Cobra using SDM:

This is the same dive using MacDive:

 

[ClayJar]

The Cobra does record your usage during the dive the problem is that SDM software does not show you that info. It only gives you starting pressure and ending pressure and an a linear graph between the 2 points. If you use a different software to extract the info from the computer you will see actual air usage during the dive.

Ah, quite interesting (and informative). Thanks for the info; I will add it to my collection.