cdreamer
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Were you diving nitrox or air? Was the computer set to air while diving nitrox?
Long deco "incident" last week
- Thread starter charlesml3
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Well not to split a hair but actually that is what tables are for. to be able to know what your limits are at various depths ahead of time so that you do not need 26 min of Deco. Especially if you do not know how to read the computer accurately. you could have used the Plan feature on your computer, but alas you did not know how to use it as you have said, but now I am just being a smart ass.
But still smart. And this is why the computer should be back up for the brain. Especially when doing multiple dives over a number of days. And a bit of common sense helps as well.
dumpsterDiver
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Do you have any idea of how ignorant those comments sound?
It is like your wife saying she got a speeding ticket while driving through the speed trap.. when you ask her the details she says she was just speeding you know.. going 95 in a 35 mph zone... no big deal.
that is a significant amount of deco!
It is quite possible that the computer failed and started to give bad readings on depth. My computer did the exact thing to me a few weeks ago and I ended up with more deco than i should have had, because the depth reading was too deep and I also ended up clearing the deco because I wanted to use the computer for another repetitive dive. The point here is that I pretty much KNEW what my profile should be, I ain't blindly following my computer!
If you don't do tables, and you blindly follow a computer, what happens when it is blatently wrong and gives you way too much no deco time??
Charles,
You don't know why it happened, you can't say what your profile was so there's no way to validate whether the computer was working correctly or not, and even now you don't think it's important enough to have some kind of backup. It sounds like you've made your choice, hopefully you find the response here that affirms whatever you're looking for.
But for the benefit of other divers reading this thread, I'd say that this is a very good reason to consider knowing the tables, even in shorthand form, as a backup to your computer; doing so will give you a sanity check if this situation pops up. On the first dive of the day, you're on air at 60ft with a bottom time of 50 minutes, and your computer says you have 10 min deco. Is that right? How about if you're 100ft for 35 minutes on 32% and your computer says you've still got 10 minutes NDL? Being able to use your brain to cross-check whatever the electronics are telling you is too huge a benefit not to take advantage of, in my opinion.
Here's one that is not overwhelming to read (optimized for 32% but also includes times for air), and can be easily memorized for key depths and times:
Instructions on use (including for repetitive dives) are available at the site. Just ignore the little frog-kicking dude if DIR isn't your thing, the table doesn't care what your diving system is
Really, as someone who has worked with technology for 30 years, I couldn't imagine trusting my life to a single electronic device with no backup. I would put it the other way, though. My brain would have to be backup for the computer. The brain has to be prepared to overrule the computer rather than the reverse.
Twenty-six minutes of deco. That's a lot of decompression. That's almost 30 minutes at 150 feet's worth of deco. That kind of display on a computer would make me VERY suspicious on a recreational dive, with a normal sized tank.
I was once on a dive at Catalina with four other people. We had all done two prior dives that day, all with roughly the same profile (maybe a couple of feet deeper or shallower, same times). We had my husband, Peter, on a Suunto; two people on Aeris computers, me on gauge mode, and the last diver on a Vytec (but she hadn't done all the dives). At the end of the day, Peter had 15 minutes of deco, and none of the rest of us had any. Since we had TONS of gas, were warm and comfortable and enjoying the Garibaldi, we hung out with Peter until his computer cleared. But I think all of us knew he really didn't have to do all that deco.
What I love about the mental profiling and deco computations I've been taught to do, is that I have a good visceral sense for where any given dive falls in the continuum -- very safe, worthy of closer attention, pushing limits, or over limits. Nowadays, when I am running the VPM software on my X1 (because it's so civilized and restrained in its messages) I pretty much know what it ought to say to me, and with rare exceptions, I'm right.
I think all divers ought to have some idea what their computers OUGHT to say to them about a given profile. Otherwise, you are truly abdicating responsibility for your safe decompression to an electronic device underwater, and to the person who programmed said device.
I was once on a dive at Catalina with four other people. We had all done two prior dives that day, all with roughly the same profile (maybe a couple of feet deeper or shallower, same times). We had my husband, Peter, on a Suunto; two people on Aeris computers, me on gauge mode, and the last diver on a Vytec (but she hadn't done all the dives). At the end of the day, Peter had 15 minutes of deco, and none of the rest of us had any. Since we had TONS of gas, were warm and comfortable and enjoying the Garibaldi, we hung out with Peter until his computer cleared. But I think all of us knew he really didn't have to do all that deco.
What I love about the mental profiling and deco computations I've been taught to do, is that I have a good visceral sense for where any given dive falls in the continuum -- very safe, worthy of closer attention, pushing limits, or over limits. Nowadays, when I am running the VPM software on my X1 (because it's so civilized and restrained in its messages) I pretty much know what it ought to say to me, and with rare exceptions, I'm right.
I think all divers ought to have some idea what their computers OUGHT to say to them about a given profile. Otherwise, you are truly abdicating responsibility for your safe decompression to an electronic device underwater, and to the person who programmed said device.
A couple of years ago I was buddied with a fairly experience diver doing two dives (dive 1 to 40m and dive 2 to 30m) on the Zenobia in Cyprus. He had just bought a Suunto Vyper computer and after reading the instructions felt that he should dial in 2+ conservatism. I was also diving using Suunto computers (but on standard settings).
On the first dive which was multi level I had no mandatory deco and he had 3mins at 3m. After a 2 hour surface interval we did our second dive on which I registered 3mins of deco while my buddy had 22! It just goes to show how much difference can be made (especially with repetative dives) if you add conservatism.
Perhaps in the case of the OP his buddy had unknowingly altered the conservatism on his computer.
Oh, and on my dives we were carrying plenty of gas having worked out that my buddy was going to have a long deco (it didn't stop our mates on the boat dropping chicken bones from the onboard BBQ down past us to encourage us to accelerate our deco!!!)
On the first dive which was multi level I had no mandatory deco and he had 3mins at 3m. After a 2 hour surface interval we did our second dive on which I registered 3mins of deco while my buddy had 22! It just goes to show how much difference can be made (especially with repetative dives) if you add conservatism.
Perhaps in the case of the OP his buddy had unknowingly altered the conservatism on his computer.
Oh, and on my dives we were carrying plenty of gas having worked out that my buddy was going to have a long deco (it didn't stop our mates on the boat dropping chicken bones from the onboard BBQ down past us to encourage us to accelerate our deco!!!)
Its quite possible that Peter's computer was functioning flawlessly. Suunto computers are know to be very conservative and I have noted many computers will get comparatievely more conservative on dive three of any given day depending on how they deal with the slower compartments in the model.
You are absolutely correct that a diver should know exactly what to expect with his or her computer. My first action with any new computer has been, if I do not know exactly what model it uses, is to run any simulation or planning software that came with it and compare it with the deco software I normally use (D-Plan) with the goal of getting the conservatism settings adjusted so that the computer and software derived deco schedules are fairly closely in sync with similar curves and run times.
If a diver just rides the computer and does not have an idea what the over all deco schedule is going to be, gas planning becomes a crap shoot and the diver also has no idea if the computer has failed and is giving faulty information or not.
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