Suunto Gekko reverted to Air and nearly ruined my day

[reefduffer]

The workaround I was thinking of was to [for example, if the target is 30% as you say] set it to 32%, accept that, quit, quit, quit etc., so the FO2 is actually set at 32, ready to dive.

Then immediately repeat, setting it back to 30. If that doesn't reset the timer, I'd be more surprised than the behavior you previously described where going through the set screen but not storing a change doesn't reset it.

On our recent trip to LC I had a chance to try this, it seemed to work.

We were diving with %O₂ set to 31 in the Cobra. Our last dive was Wednesday ending at 11:51 AM.

At 7:02 AM Thursday I still had 0:38 No-Fly time left, and %O₂ was still at 31. I set it to 32, saved that off, exited SETDIVE, back to the ready-to-dive screen. Then immediately went back and set it to 31, and again exited to ready-to-dive.

At 8:30 AM the No-Fly had cleared. The %O₂ was still at 31.
My wife's Cobra, which had been on a very similar profile to mine all week but hadn't been reprogrammed with the workaround, also had the No-Fly cleared, but was now at 21%

At 9:18 AM (Roughly 2:10 after I set it) was still at 31, which surprised me a little, but the manual says
Manually entered values for oxygen percentage are retained for about two hours after the setting if a dive series has not started.
I wonder what the time interval is, odd that it wouldn't be exactly two hours, but the manual does say "about".

In any case, I next had a chance to check it at 10:55 AM, and it was at 21%.

I haven't had the opportunity yet to observe the oddity reported above by HenrikBP of going through the SETDIVE->NITROX screen but still resetting to 21% when the No-Fly expires, I'll accept that it happens. But this workaround procedure seems to work.

I've been mulling over the design decision. I can't really convince myself that there's a case for this being the appropriate behavior; if you go to SETDIVE->NITROX and look at the display saying e.g. 31%, the reasons for resetting it to 21% at the end of a dive series, if that's less than two hours later, don't seem to apply. Maybe I'm missing something.

But between an effective workaround if you know to use it, and the %0₂ there to check in the middle of the screen when you check your tank pressure before entry, I guess it can be lived with. Anyone know if the newer Suunto's have the same issue?

 

[drbill]

My old Uwatec put itself into 50% O-2 all by its lonesome when I've always had it set for air. Very strange behavior when a dive computer decides it can choose it's own mixes for you.

 

[DwayneJ]

Not to beat a dead horse String, but I would take exception to your statement that it is "Well known that Suuntos and other brands will revert to air after a specific time surface interval." It might have been well known to you; but if it were "well known" as you say, then I would have known it before the incident and it would have never happened.

Sherwood Wisdom II also reverts to air mode. It's in the manual.

* Diving Nitrox, yet did not validate computer settings before the dive.
* Diving deco relying on a single computer without backup tables
* When the computer freaks, the dive continues instead of being aborted.

Do a Tech course and get the right equipment.

Dwayne