Vyper Question?!?

[Wbwilly]

Last week my vyper really confused me. On Thursday I made four dives...9am & 11am-4pm & 6pm...the standard Cozumel two tankers without any problems. During my first Friday morning dive my Vyper started showing me a 5 min ascent time. OK...no big deal with the drifting ascents and safety stops. My ascent time eventually got up to 14 min so, after about 50 min, I made my way slowly to 20 fsw to hang out for a while. Well, I hung out between 15-20 fsw for another 40 min and the Vyper only counted off 4 min of the ascent time. So, here I am with a 90 min dive, 40 min of which are between 15-20 fsw. The DM has dropped a tank and reg down for me but with app 700 psi showing I was OK. Confused, I decided to make the final ascent and of course the Vyper started acting like an irate boss.

OK...I violated the computer...Here's the next strange part. I had already planned to skip diving the next day so I got in the plan mode giving myself a 48 hour surface interval and all was well with the Vyper...Yet, when I backrolled 48 hours later it went straight to Er so I could only use it as a gauge. I stayed 10 fsw above the DM for the dive and made xtra long drifting stop. I was fine but the Vyper didn't want to cooperate.

Anyone have anything similar to this???

 

[Kim]

Is the battery still ok? If it is then it sounds like something is wrong with the Vyper. Have you checked your dive profile against tables to see the difference?

 

[Wbwilly]

Thanks Kim...yes the battery is due for a change although it only started saying " low " on this trip. I did check my profiles against the tables and all should have been good. Maybe the low battery and the conservative nature of this computer are the culprits.

 

[Kim]

Thanks Kim...yes the battery is due for a change although it only started saying " low " on this trip. I did check my profiles against the tables and all should have been good. Maybe the low battery and the conservative nature of this computer are the culprits.

I reckon it'll be the battery - they drop out very quickly when they are finishing and the computer will start to do weird things - I don't think that it's anything to do with the conservatism of the Vyper - sounds more like incorrect computations probably due to vascillating voltages. I'd change the battery and see - they don't cost much!

 

[String]

Definatelu battery related.

They're cheap and user changable so no excuse for not changing it

 

[Spectre]

It's always a little tricky to actually know exactly what the computer sees vs. your description. If you could download the dive; and post a screen grab of the dive profile with the curser sitting at the point where you start your ascent; we probably would have a better idea as to what it was thinking.

 

[Wbwilly]

Thanks guys...I'm changing the battery as we speak and I'll test it in a quarry soon. Hopefully it will feel better with new juice.

 

[miketsp]

My Vyper has occasionally given me long hang times which did not make sense in real time but working through the replay on the SDM, did.
Sometimes mixing deep and shallow dives the slow compartments get very loaded and deco stops really extend.
After downloading the profiles to the SDM it should be obvious if there is an error or not. The SDM recalculates the N2 loadings based on the recorded profile, so if the profile looks correct, the SDM deco recalcs should match up closely with what the computer told you to do in real time. The only difference is provoked by the sampling interval.

If you ever want an opinion, you can always save a copy of the sdl file with a new name, delete the non-relevant dives, save it, zip it and post it here as an attachment.