Suunto Gekko reverted to Air and nearly ruined my day

[handben]

That why I said you should have aborted the dive we your computer hit deco.

I certainly could have turned the dive at that point. The thought briefly entered my mind. I'm glad I didn't though as I would've missed out on the next 45 minutes of diving. (It ended up being a 68 minute dive). I would have gotten back on the boat after about 20 minutes (or less); but then I would have been regretting my decision for weeks (probably until my next trip in November). I try to make the most of the limited time I have available for diving.

 

[leapfrog]

I dove without a computer for some 24 years and did quite a few dives just fine without one. Now I don't know about you, but I'm just not out 20 miles at sea 120 feet down with a couple of good buddies all that often. I'd much prefer to dive (conservatively) than abort a dive due to a computer glitch. But maybe that's just me.

If you dived without a computer for 24 years, did you do it using tables, SPG and a dive watch? Now that you have a PDC, do you not take the tables and the dive watch with you anymore? (I'm asuming you still use a SPG). Have you thought about having a back up PDC?

 

[handben]

If you dived without a computer for 24 years, did you do it using tables, SPG and a dive watch? Now that you have a PDC, do you not take the tables and the dive watch with you anymore? (I'm asuming you still use a SPG). Have you thought about having a back up PDC?

Leapfrog, I dove with a SPG and a dive watch and tables (used the old PADI tables which were based on the Navy tables). I still use an attached SPG. I don't trust the electronics of an air integrated computer. To be frank, I don't carry the tables in my bag any more. It'd be a good idea though, and I think I will put them back in there for my next trip. I do find that for most of the type of dives that I do, I can get a lot more time per dive with a computer within no decompression limits than I did diving tables. This is particularly true when diving walls. Also I come up much slower now using a computer (with the bar graph showing ascent rate). When I was trained, the standard was 1 foot per second and the concept of a safety stop was not yet widely adopted. I remember having lots more headaches after dives in those days. I may start using a back up computer; it is always a balancing act for me to try to streamline my configuration and having redundancy (I haven't adopted a pony bottle for this reason).

 

[redacted]

I had a dive computer (brand unnamed) which switched from air to 50% nitrox and told me I was dead on a dive. It did this several times although to varying mixes. It now rests in a garbage dump somewhere near the manufacturer's head office!

Another one loved to tell me I was ascending too fast when I was stationary at depth filming.

The second turned out to be a dying battery. The first may have been the same, but the battery required factory servicing.

Bill, I would have bought that old Oceanic Data + from you.

It resets to 50% O2 and 79% N after every nitrox dive. So you have to input the mix before every subsequent dive. Worse than that, after 12 hour SI it goes to sleep. It still runs offgassing but must be recycled before you can dive. But you can't recycle at 11 hours 59 minutes; you must wait until it takes its nap. A real PITA as you get ready for a morning dive after a nigh dive the day before.

 

[leapfrog]

I don't trust the electronics of an air integrated computer.

Wise.

To be frank, I don't carry the tables in my bag any more. It'd be a good idea though, and I think I will put them back in there for my next trip.

I do find that for most of the type of dives that I do, I can get a lot more time per dive with a computer within no decompression limits than I did diving tables.

I am a great fan of PDCs. It's just a question of redundancy, as you point out in your post. If you are going to trust your life to a PDC, you want two. Otherwise backup with a dive watch and tables. Still a good habit to plan the dive using tables.

Also I come up much slower now using a computer (with the bar graph showing ascent rate).

Definitely one of the many advantages of PDCs as long as they work! Otherwise, back to good old bubble ascent rate!

When I was trained, the standard was 1 foot per second and the concept of a safety stop was not yet widely adopted.

Now we teach a maximum of 18 meters/60 feet a minute from 30 meters to 18 meters and 9 meters a minute from 18 to 6 meters. Minimum safety stop of 3 minutes between 5 and 6 meters.

I remember having lots more headaches after dives in those days. I may start using a back up computer; it is always a balancing act for me to try to streamline my configuration and having redundancy (I haven't adopted a pony bottle for this reason).

I really don't think two wrist mounted computers instead of one will affect your configuration very much.

 

[H2Ohm]

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

Well, I teach my students to never, ever share computers. If your computer failed then you should've ended your dive...period! Did your buddy's computer have the same exact number of dives and dive profiles over those multiple days? Regardless, I just do not think that is safe diving practice from the quote above especially when doing deco dives.

If you dive with a computer then you should follow YOUR computer even if it means ending a dive early. It's only your life you're gambling with.

I truly hope you learn something valuable from this. Good luck...

 

[handben]

H2Ohm, I think that it is sage advice to not share computers. IF I were an instructor, I'd certainly teach that to my students. Just as a physician, I give health advice that is more conservative than what I might practice in my own life. However in this case, my buddy and I had the same number of dives; his profiles were slightly more aggressive than mine had been on our 3 previous dives together. So his computer had a bit more nitrogen loading than mine and our final dive was a relatively shallow (by NC standards) 60 foot dive with no deco. I knew that I was being ultra cautious with my deco on my first dive of that day, as I did more than twice what was required for the nitrox mix I was diving (though still not enough for 21% as the computer was calculating the dive). The issue in my mind was whether to stay in the water an extra 10 minutes hanging on the line and inconvenience the 20 folks on the boat in order to satisfy the computer, though I knew I had done way more than enough deco at that point. I had plenty of air but decided it wasn't right to make every one else keep waiting, at this point my dive time was at 68 minutes. But again, I agree with your advice to not share computers and not ignore your own computer and would not advocate any others follow my example on this dive. In the end though it was a great dive.

 

[Dave1981]

No one seems to have mentioned the dangers of a backup computer here? Unless of course you're diving with it in your BCD pocket or something it won't have the same O2 exposure or residual nitrogen to give you the correct profile for your next dive. Or is that just assumed a given... I do try never to assume.

IMO take the tables with you and a watch. If you know your dive plan, you can continue to dive to that even if the computer breaks half way through one dive, then use the tables to calculate subsequent dives based on a conservative dive profile of the previous dives.

Also for the suunto question, it will reset to 21% on subsequent dives (and rightly so I think). It kind of becomes standard practice to set your computer after testing the tank, you have to make sure though that you don't just get to the O2 and quit, but get it flashing and save. Then it's fine.

 

[leapfrog]

No one seems to have mentioned the dangers of a backup computer here?

My definition of back up is that you dive with two computers with the same algorithm at the same time.

Unless of course you're diving with it in your BCD pocket or something it won't have the same O2 exposure or residual nitrogen to give you the correct profile for your next dive. Or is that just assumed a given... I do try never to assume.

You should have both on the same wrist, one on each wrist or one on your wrist and other on you console.

IMO take the tables with you and a watch. If you know your dive plan, you can continue to dive to that even if the computer breaks half way through one dive, then use the tables to calculate subsequent dives based on a conservative dive profile of the previous dives.

Exactly.

Also for the suunto question, it will reset to 21% on subsequent dives (and rightly so I think).

In fact most (all?) computers do. Does anybody know of one that doesn't? I would be interested to read about it.

 

[ianr33]

In fact most (all?) computers do. Does anybody know of one that doesn't? I would be interested to read about it.

Aeris computers (or at least the Atmos Pro) retain the nitrox mix if you have "FO2 Default OFF " selected.

Shearwater computers retain all mixes until changed manually.

I have found that reading the manual helps................................