Altitude And Computers

[ERIC.K]

Here is a Question. I purchased a new vyper, wrist model, learned and played with every function before it got wet. Packed it up into a carry-on bag and boarded a plane bound for the bahamas. Once there I strapped it on, turned it on and giant strided right in. What I can remember now after the fact is that once the computer came on to the surface mode...or the pre-dive mode where the depth is desplayed it registered 12 feet and really I just jumped in. In retrospect I should have investigated this but the first dive of the trip. My problem came after a normal safety stop for 5 minutes but once back on the boat, my computer still read 12 feet and the vyper did not acknowlege that I was at the surface. well my dive time just continued to tick. I was angry to say the least. My wife suggested to me that I take the battery out. I did and the computer functioned fine the rest of the trip and logged 22 dives, minus the first dive. and my question is........while in my carry-on in the overhead bin. could my vyper have come on and tried to measure the depth, and caused and internal malfunction? due to the aircraft pressurized cabin? I carry a console depth gauge and the depths measured equally. any thoughts. seems to work fine now

 

[Warhammer]

Hmmm, that's strange. Alot of computers automatically adjust for whatever altitude you happen to be at, and if you turned it on while on the plane it would adjust itself for the cabin pressure. Which I believe is 8000ft. But even then, it should re-adjust itself once you're back at sea level. But the Vyper isn't one of these computers. You have to adjust it manually, so I'd think something went haywire with it.

 

[Rick Murchison]

12' is too deep to have been caused by activation in the aircraft, even if the in-water contacts somehow got wet. If that were the problem you'd be looking at about 6 to 8 feet.
This is the third case of inaccurate depth reading I have heard about (I have personally seen two) in the Vyper/Cobra computer. It appears to be very random, and as I'm intimately familiar with the history of the two I've seen before your report, I can tell you that one of them was inaccurate on two of about a hundred dives; the other on one of about a hundred dives. Both of these computers had all their inaccuracies in the first few dives after they were new.
I recommend you carry a backup depth gauge if you're going to dive the Vyper or Cobra.
I do.
Rick

 

[Warhammer]

Glad you brought that back up, Rick. How are those computers doing now? Have you noticed any inaccuracies since those that posted when they were new? Both my Cobra and my wife's Vyper now have about 50 dives on them and I haven't noticed anything out of the ordinary with either of them. I have cross checked them some, but I surely could have missed it. My biggest complaint with the Suuntos thus far is that blasted CBT graph. I really wish they had a nitrogen loading graph instead.

 

[Rick Murchison]

Since the initial errors we haven't seen any on either of the two. I sent the Cobra (that's the one that had two different "bad" dives) back to Suunto where they tested it and claimed they made no fix and sent it back, and it has operated flawlessly ever since. I do not trust it, however (fool me once, shame on you... fool me twice shame on me) and *always* carry a backup when diving the Cobra.
My friend's Vyper has only malfunctioned that one time - but it was enough that he also always carries a backup.
Rick

 

[donooo]

I don't know about your computer but the Cochran Commander is always "on" , keeping track of pressure,, maybe it needs to "time out" or "correct" , like time to fly or something. Off doesn't nesscesarily mean not doing something ,,, like monitoring pressure. Or my bottom timer is off, but keeping track of time.

good luck don O

 

[Radioactive]

Eric,

Although I am not familiar with your Viper computer, the actual decreasing in atmospheric pressure from the aircraft’s climb to altitude and the repressurization of the cabin would in theory have the opposite effect, i.e. it would be reading negative depths if it could.
As I live in Wyoming, at an elevation of over 5,000 ft, all my diving here is considered High Altitude diving, however when I travel, it can take up to 24hrs (althought I have never seen anything greater than 10 hours) for my computer to recalibrate the altitude based on the barometric pressure. Not knowing the elevation of Cincinnati, not allowing the computer to adjust for the change could have created the malfunction.
The problem you are describing is frequently seen in dive watches that are not allowed time to recalibrate due to changing elevations (been there done this one). Hope this helps some.

 

[Ber Rabbit]

Radioactive, FYI Cincinnati's elevation is between 900 and 1000 feet I believe. I know Brookville, OH (about an hour north) is at 1040 feet.
Ber

 

[Norm]

Not taking a stand either way ERIC, but I would have pass on this fact: I have heard of several other divers that have either intentionally, or accidentally, turned their computers on at altitude and experienced the same phenomena!
(If mine is already running/deco'ing when I board a plane it causes no problems - but that's a different story)
Norm

 

[Ari]

The Vyper is not altitude self adjusting. Electronic units can some time just go crazy. Don't try to understand it, just accept it (although I know ot doesn't sound too good).

When something like this happens, and nothing else seems to work, taking out the battary, including all other backup or power supplies, and leavng it out for a couple of minutes, should do the trick, reverting the unit to its default settings. It did in your case.

Sorry for not being able to come up with something wiser.

Ari