Suunto Cobra dive/download different

[bwaters]

Concerned after downloading my dives from the weekend. (Actual) The last dive I went into deco at 37 minutes. Had an ASC of 4 minutes. Stopped below ceiling depth until ASC disappeared. Ascended to Safety Stop Depth and monitored my 3 minute countdown. Plenty of air so I stayed an additional 3 minutes. All looked good so I went to the boat.
(Download) Shows deco time 0 & ASC time much earlier, but only deco symbol is at the 37 minutes. Most of dive was flashing the ASC. The dive ended with 5 minutes of ASC remaining. No safety stop ever showed on profile.

Computer never locked out (Er).
Any comments/ideas???

 

[Scubamedicjoe]

hum . kinda strange I have been diving the cobra for close to three years and never had a Problem with mine yes it is a very conservative computer, but there is reason for that it, algorithm they use . also what sampling rate do you have yours set on change it to 60 secs and it becomes closer to most other computers.just a though with out being there and seeing the down load.

 

[medical1]

Was doing 3 training dives on mothers day. No problems on my first dive but on my second dive while accending from 45' my computer told me I was at 0' while I was still 7' under water. My backup depth guage confirmed I was at 7' as well as looking up and still seeing the wet stuff :scubadive. Made a 3rd dive to 100' with the cobra and my backup with no problems and the computer giving accurate readings verified by my backup & 2 other divers computers while still at 100' :06: My cobra NEVER gave me any problems before & when I downloaded the profiles of the dives the information was correct. VERY Strange but glad I at least had and will continue to dive with a backup depth guage since I dive with nitrox & worry about MOD.

 

[Scubamedicjoe]

also what program number do you use i am using there sunnto 1.6 and all seems ok with it so far.

 

[medical1]

I' using version 1.51 with no problems. Other then bug fixes on version 1.6 are there any enhancements to the program? Not going to upgrade if theres no reason too

 

[bwaters]

I was using the older 1.4, but have just upgraded to 1.6. I couldn't tell that anything changed. I sent an e-mail to Suunto asking if they could explain, but haven't heard anything yet.

 

[diver_paula]

I'd keep monitoring actual vs. download. I had a problem with my Solution a few years back. I'd be at 100' it would say I was on the surface. & was very glad I always dive with a Companion as a secondary computer.

Anyway, I've always been extremely happy with my Suuntos. Went into my LDS when the Solution continued to act up. (Up until then, it had worked perfectly for the 8 or 9 years I'd been using it.) They called Suunto who said mail it in. A short time later I had a fixed Solution and a new scratch guard. No problems since.

Paula

 

[medical1]

I'd keep monitoring actual vs. download. I had a problem with my Solution a few years back. I'd be at 100' it would say I was on the surface. & was very glad I always dive with a Companion as a secondary computer.

Anyway, I've always been extremely happy with my Suuntos. Went into my LDS when the Solution continued to act up. (Up until then, it had worked perfectly for the 8 or 9 years I'd been using it.) They called Suunto who said mail it in. A short time later I had a fixed Solution and a new scratch guard. No problems since.

Paula

Paula
Thanks for the response I was diving with my DM who sold me the Cobra new & saw the computer act up. When I surfaced from my second dive my computer read 45' max on the dive although my DM said we were at 51'. No problem on the 3rd dive to 100' though. Diving again this weekend with my DM, Cobra & backup guage. May talk to him about sending it in to Sunnto for a check-up.

 

[bwaters]

Received a response from Suunto on the subject. This gives me a better understanding, but still have the uncomfortable feeling when it APPEARS that I have violated a deco stop. Just have to cut back on the minutes.

"Thank you for contacting Suunto.

This is because the dive computer stores the dive profile as single points (according to sampling rate). The SDM then uses these values to recreate a dive profile, and it rounds up a bit more conservatively, and can then show a no-deco dive as a deco-dive in the Dive Manager. The smaller you set the sampling rate, the smaller the difference gets.
Remember that the software uses a 20-second sampling rate (or 10, 30 or 60 seconds.), whereas the Cobra makes nitrogen calculations every second during the dive. If you came close to decompression, the software uses 20 seconds at depth instead of 1-second. This can make a big difference when calculating decompression.
Please also keep in mind that the SDM software only represents a re-creation of the data shown during the dive, and does not correspond 100% to the data displayed during the dive."

Suunto - Great computers and prompt support. Just a couple of reasons why I think they are outstanding!