Suunto Vyper issue

[Maples]

Hi All

I had an issue with my Vyper on the weekend and rereading the manual has given me no answers so I thought maybe someone here could formulate an explanation.

I was doing my deep certification and my dive stats were as follows:

Dive One
Max depth 31m
Avg depth 17.1m
Total dive time 25 min

SI 21min

Dive Two
Max depth 32m
Avg depth 14.1m
Total dive time 24 min (Inc 8 min stop @5m)

SI 55min

Dive Three
Max depth 33m
Avg depth 17.4m
Total dive time 26min

I was diving air not nitrox.

The third dive saw my NDC time get pretty short (1min @ 17m) where my instructors less conservative computer was giving him 5min. So we ascended to 9m as the policy with this particular company is 3min@9m plus 3min@5m. It was at 9m that the Vyper went a bit nuts. It wasn't extending the NDC limit at all as I was ascending, and whilst sitting at 9m (8.5-9.5) the NDC time was jumping around like crazy, giving me anywhere from 2min to 54min and everything in between. I can't find a reason for this. It gave me no ceiling limit or other indication that I had gone into deco, and checking the tables manually sees my profile finish in about pressure group R.

Has anyone else had a Suunto go nuts on its NDC like this and does anyone have an explanation? The battery check is fine but I'm wondering if I should put the thing in for service and a battery change regardless.

 

[tstormdiver]

Not sure exactly what is going on there with yours, but you may want to have your LDS or Dealer you got the computer through call Aqualung (Suunto is sold through Aqualung) about the issue. It may need to be sent back. Suunto's quality seems to be slipping some lately. I recently had a malfunction with my HelO2 & know of issues with Vyper Airs & other computers. I was doing OW dives with students in an area of the local quarry that has a maximum depth of 25 ft. When I came off the last dive, the computer was registering a max depth of 472 ft:shocked2:. I have dove all over that quarry & know there is not any area that exceeds 120 ft. (I sure whish I could have find that hole again,.... the narcosis must have been so bad, I can't remember a thing about it:loopy: .) Any way,... I wound up getting a new copmuter out of it.

 

[DevonDiver]

Given the very short surface intervals (!), it isn't surprising that the computer wasn't extending your NDL upon ascent. You're into the realms of slow tissue saturation, so you shouldn't expect it to clear quickly (as it would on a series of shallower dives).

As for the 'jumping' NDLs... sounds like a glitch to me. I've dived a Vyper for the past 10 years (incl lots of deep dives and deco) and never experienced that.

 

[bleeb]

Given the very short surface intervals (!), it isn't surprising that the computer wasn't extending your NDL upon ascent. You're into the realms of slow tissue saturation, so you shouldn't expect it to clear quickly (as it would on a series of shallower dives).

+1

From what I've read elsewhere, the two-phase gas model the Vyper tends to off-gas proportionally less during SIs less than an hour. (IIRC, some Doppler ultrasound studies have found the peak in detectable blood bubbling is between 50-70 minutes after surfacing, although there's some uncertainty as to how accurately this represents actual bubble content.)

 

[Hatul]

If the display is unstable as you mention than I would suspect a problem with the unit.

I have two comments. I did several dives now with both my Vyper and my new Uwatec Sol. On the first dive the Vyper was more liberal but on repetitive dives the Suunto was much more conservative. Your surface interval after the first dive was very short and I'm sure the Vyper would penalize you heavily. My understanding is that after such a deep dive your SI should be at least an hour to reduce the amount of silent bubbles which can act as seeds for bubbles on your next dive.

 

[Maples]

Thanks for all your thoughts. I have been using this unit for 4 years and it was hubbys' for 2 years prior to that and it's never had an issue before.
It was the instability of the NDC display that really threw me, the short times I completely understand given the dive profile.
FWIW I was a bit dubious about the short SI between dives 1&2 but was reliant on the fact that the instructor would have done his calculations and found it to be an acceptable profile. I didn't make those calculations myself nor use the planning function available to me on the vyper. If anyone other than an instructor had suggested such a profile I probably would have checked it for myself. It was an acceptable profile but certainly not an ideal one. It was done that way such that we could fit 3 dives in whilst the rest of the charter did 2 at their own pace. Commercial reality.
Next step is to find the Suunto/Aqualung agent and send the Vyper in for a health check.
Thanks again

 

[Tortuga68]

Before you do that I would suggest an overnight soak in fresh water. If the battery is the problem (which it may be, despite the battery indicator display) it should confirm it; if you have salt crystals partially blocking the pressure sensor, it should fix it

 

[DevonDiver]

FWIW I was a bit dubious about the short SI between dives 1&2 but was reliant on the fact that the instructor would have done his calculations and found it to be an acceptable profile. I didn't make those calculations myself nor use the planning function available to me on the vyper. If anyone other than an instructor had suggested such a profile I probably would have checked it for myself. It was an acceptable profile but certainly not an ideal one. It was done that way such that we could fit 3 dives in whilst the rest of the charter did 2 at their own pace. Commercial reality.

FWIW, as an instructor, I wouldn't put convenience about safety and I certainly wouldn't be doing repetitive deep dives without, at least, a 1 hour SI.

 

[ajduplessis]

First off the SI times for the depth you dived is not recommended and the Suunto RGBM algorithm will penalise you by reducing NDL on repetitive dives. The problem with varied NDL times in the shallow is a potential problem and could be anything from battery, faulty pressure sensor and many more. I would have it checked by a technician.

I would like to come back to SI you had between dives. They are very short and it’s the diver’s responsibility to conduct their own planning. IMO this falls into a “trust me” dive category. If you look at air dive tables and use average depth and time, you climbed out of the water as a C diver (avg 17m rounded to 18m @25min) and returned on your second dive as B diver after 21min SI and then also complete a 3rd dive!!!

All 3 dives were below 30m (100ft) with 76min (1hr 16min) SI in total for all dives. This is not good dive planning!!!

After the first dive you should have potentially seen a triangle with a ! sign in the top right hand corner of your dive computer. This symbol indicates that the diver should consider/recommend EXTENDING their SI time.

 

[Tortuga68]

After the first dive you should have potentially seen a triangle with a ! sign in the top right hand corner of your dive computer. This symbol indicates that the diver should consider/recommend EXTENDING their SI time

Wow, a psychic dive computer - what will they think of next