Suunto Gekko reverted to Air and nearly ruined my day

[handben]

I was recently diving off the North Carolina coast on the "Papoose" when I ran into trouble with my computer. It was my second day of diving. The first day was just fantastic. Diving on nitrox 30%, I dove the Spar with a max depth of 113 feet and a dive time of 42 minutes. It was one of my all time favorite dives with many sharks and immense schools of fish. This was followed by a dive on the Aeolus wish a max depth of 118 and a dive time of 43 minutes (after an hour and 20 minute SI). Both dives were great.

The next morning the winds had picked up somewhat, but not horribly. We were heading to the Papoose with a max depth of 121. I figured I'd lengthen my bottom time by going into deco a bit. On the dive boat I consulted my computer and was looking at the NDL numbers for the various depths with Nitrox 30% (as it had been set the previous day). I went ahead and geared up and jumped in. Things started off great. There was a moderate current but good vis and lots of fish. About 10 minutes into the dive, my computer started beeping at me. I looked to try to figure out what was going on and realized that the computer had reverted back to Air mode and that it already had me going into deco. I was only about 1/8th of the way into my tank and certainly didn't want to force my 2 other buddies to cut their dive short. So decided to keep diving and would basically go by one of my buddies computers since it was correctly set for Nitrox 30%. We went ahead and had a pretty nice dive. After going through a bit over half our tanks, we decided to head back up and do out deco stops. My buddy had about 8 minutes of required deco according to his computer, and I had 28. What a pain. I did not want to violate my computer, so decided that I'd wait it out. So I hung and hung and watched practically all of the divers still down come around me on the line. Most had already boarded the boat by this point. There were still 2 straglers who happened to also be the first ones in the water. They were actually diving with rebreathers. Once they boarded the boat, I knew that I was the last one still in the water, and my computer still wanted me to hang for 10 more minutes (though my buddy had been finished with his deco for about 10 minutes). Although I still had about 750 pounds left, I decided to not make the whole boat wait on me, just to keep the computer happy. So I came on up and it beeped and beeped at me; then went to "Err" message, and I was locked out so to speak for 24 hours. I went ahead and made my next dive using my buddies spare computer (that he had taken on the previous dive as well) and used it for my second dive; which was a much less demanding profile. But the whole incident played heavy on my mind and made the first dive much less fun, as I was having to concentrate more on equipment issues than the dive itself.

The leason I learned is to be darn sure to set your computer correctly Before the dive. I hope this helps others who are planning similar dives. Ben in Baltimore

 

[bamamedic]

Computer issues are no fun...it's amazing how easy it is to become dependent on a little piece of gear, and when it breaks, it ruins one's day.

Might not be a bad idea to start carrying a backup computer on those dives where you start to head into deco. On that note, also might not be a bad idea to take a course in decompression procedures, if you're going to be going into deco. I learned one hell of a lot from that course.

Does the Suunto Gekko have a "reset" button? I've bent my Nitek Duo, used the "reset" button, and was able to continue to use it (taking into account the fact that it had cleared the previous dive from it's memory, of course)

 

[Doc]

....and was able to continue to use it (taking into account the fact that it had cleared the previous dive from it's memory, of course)

Exactly how does one take that into account?

 

[reefduffer]

... About 10 minutes into the dive, my computer started beeping at me. I looked to try to figure out what was going on and realized that the computer had reverted back to Air mode and that it already had me going into deco. ...

The leason I learned is to be darn sure to set your computer correctly Before the dive. I hope this helps others who are planning similar dives.

Not being confrontational, but I'd just like a little more precision as to what happened here. I dive a Cobra; I think except for the AI (not involved here) and a few bells and whistles, the Gekko, Vyper, and Cobra are really the same computer, so you've caught my attention.

I'm guessing that your computer did not "revert back to Air mode", it reverted back to 21% O₂. I'm not picking pepper out of fly****, these are two separately managed configuration parameters in these computers. The mode, or model, one of [air, nitrox, guage] does not change autonomously unless your computer is broken in a very unlikely way. The FO₂, on the other hand, does. From the Gekko manual page 27-28:

3.4. DIVING IN NITROX MODE
3.4.1. Before Diving
The GEKKO can be set for diving with standard air only (Air mode) or it can be set for diving with Enriched Air Nitrox (Nitrox mode). If you are educated for nitrox diving and you plan to make nitrox dives, it is recommended that you set the dive computer permanently to its NITROX Mode. The Nitrox mode can be enabled by accessing MODE-SET-MODEL (see chapter 4.2. “Set Modes”).
...
In the NITROX Mode, when set to standard air (21% O2), the instrument can be used as an air dive computer. It remains in this air mode until the O2% setting is adjusted to any other percentage of oxygen (22% - 50%).

NOTE! The computer will automatically revert to the air (21% O2) setting when a new dive series is started, if it is not set to any other mix during the last two hours. When the oxygen percentage is set for air, the computer will retain this setting.

Manually entered values for oxygen percentage are retained for about two hours after the setting if a dive series has not started. In case a dive series is started, the set value is retained until a new dive series is started or a new value is entered manually.

So, first dive of a new day with a SI long enough to clear the no-fly time (see page 31 on dive numbering), FO2 has reverted to 21% as designed. The Gekko has probably not reverted to air mode. I think you've got the bottom line correct in your last sentence, but maybe not quite with the meaning you intended. Or maybe you know all this and it's just the wording we're discussing.

But also, in nitrox mode, the FO₂ is displayed in really big numbers in the left middle of the screen (page 28). Not a hidden-away thing that's hard to check.

In any case, I expect your Gekko has not misbehaved, which might be the take-away of some readers of your post.

 

[bamamedic]

Exactly how does one take that into account?

I guessed

I did my safety stop on O2 instead of 32%. It was a cave profile, so my last dive was the same as the dive my 'puter got bent on. Plus my buddies were all diving Duos on the same mix, so it wasn't too hard to figure out. I figured that doing a 5 min safety stop on O2 more than covered for my computer boo-boo.

 

[handben]

"

Not being confrontational, but I'd just like a little more precision as to what happened here. I dive a Cobra; I think except for the AI (not involved here) and a few bells and whistles, the Gekko, Vyper, and Cobra are really the same computer, so you've caught my attention.

I'm guessing that your computer did not "revert back to Air mode", it reverted back to 21% O₂. I'm not picking pepper out of fly****, these are two separately managed configuration parameters in these computers. The mode, or model, one of [air, nitrox, guage] does not change autonomously unless your computer is broken in a very unlikely way. The FO₂, on the other hand, does. From the Gekko manual page 27-28:"

Reefduffer, I suspect you are correct. It probably stayed in nitrox mode, but changed the FiO2 to 21% rather than 30%. Which renders the same effect. What had confused me though was just a few minutes prior to my dive the computer was showing FiO2 of 30% in the planning mode. I figured it was already set up for this for the next dive. I didn't go back into the setup and specify 30% again prior to the dive. It came as a big surprise when I looked down and saw 21% while on the dive. As far as I can tell, you cannot change the FiO2 setting once on the dive with this model (Gekko). Clearly from now on, I'll remember to specify the FiO2 in the setup prior to each dive.

 

[HenrikBP]

I had a similar thing happen to me with my Vyper. I fortunately caught the "reset" before jumping in. But it was odd as I suspected it might happen and therefore went into the "Nitrox" setting and re-saved the 30% setting about 15 minutes before the dive. But the Vyper still reset just before I jumped in.

My guess is, that since I didn't actually changed the oxygen percentage, it didn't actually "reset" the timer.

Henrik

 

[TSandM]

There is a certain time that can elapse before the Suuntos reset to 21% (I think it's 24 hours, but it may be shorter). I know that several people I know (myself among them) have had this happen. It was the final straw that resulted in me going to gauge mode and running my own profiles, because the computer put me in deco and then in violation, and I ignored it, knowing it was wrong. So then I figured if I were going to dive and ignore it, I might as well skip the misery of the Error message

 

[reefduffer]

I had a similar thing happen to me with my Vyper. I fortunately caught the "reset" before jumping in. But it was odd as I suspected it might happen and therefore went into the "Nitrox" setting and re-saved the 30% setting about 15 minutes before the dive. But the Vyper still reset just before I jumped in.

My guess is, that since I didn't actually changed the oxygen percentage, it didn't actually "reset" the timer.

Henrik

Now that's interesting. If it really works that way, I'd call that a bug. You entered the set-% screen, even if you don't change the value, you should be considered to have viewed the current FO2 setting and "declared" it valid.

Sounds like a tedious behavior for a user to verify/test, though. Note there are two timers; the two-hour one is a pain but manageable; the no-fly one, not so much.

I suppose a workaround would be, on the first dive of a day, change it up or down one click, then change it back. Thanks for the heads-up; I may actually start doing that when I'm on a trip diving nitrox multiple days, and if I think I have a chance to verify the behavior you describe, I'll look for it.

I don't consider the revert-to-21%-when-clear designed behavior to be a bug, I actually think it's pretty thoughtful interface design. The astonishment factor, and DCI risk, of the computer assuming the FO2 left over from last use, perhaps months ago, seems greater than the way it works.

 

[HenrikBP]

Now that's interesting. If it really works that way, I'd call that a bug. You entered the set-% screen, even if you don't change the value, you should be considered to have viewed the current FO2 setting and "declared" it valid.

As you describe, I entered the set %-screen, pushed the number up and down once or twice and settled back on 30% and hit ok. Not sure what else I could have done to avoid it.

Henrik