Banned from diving for a locked out backup computer?

[Diver Dennis]

Excellent response Dennis! Good point!

Thank you. As I said, I'm not looking for a fight here. I do agree with your point that a lot of divers don't plan dives properly, with or without a computer. Too many depend on their computer only and even then I've seen way too many that just blindly follow the DM or instructor, not keeping track of depth or air. That's why DMs keep asking how much air their divers have left.

We are all different in the way we perceive technology as well. I think computers can be a great tool but I also know that water and batteries don't mix well which is why I not only carry the second computer but back SPG and depth gauge too.

 

[gcbryan]

Keep in mind that you should know what you are doing and the computer is there as a backup more or less and as was said already you are responsible for keeping yourself safe.

As was also pointed out why would you lock out your computer? If the more conservative one goes into deco just extend your safety stop by however long the computer is telling you to take a deco stop. Unless you are really screwing up it won't be long.

No diveop will require 2 computers so if you did lock one out just put it away. But there is no reason to cause it to lock you out.

There is nothing wrong with an Aeris either. If it is too liberal for you just use it more conservatively. Tell yourself that when it indicates 5 minutes until you would hit the NDL that you will go up. You don't have to wait for it to hit zero.

 

[diver_paula]

On group dives, you never have to go up before the folks with the Pelagic computers? (Oceanic, Aeris, Sherwood) If I am reading the specs correctly, Suunto users should have to go up before them everytime unless they are choosing to end their dives early or have their Pelagics set more conservatively.

I dive with two Suunto computers and can't say I've had noticably shorter dives than my buddies. A minute here, a minute there, big deal! & that's after several years of diving with them. However, I have noticed the Suuntos want a slower ascent rate than many other computers. & depending on the profile of a dive, there are times the Suunto needs a longer SI before giving me the same bottom time for the next dive as other buddies computers. For my diving the difference is typically only a minute or so once our SI goes over an hour.

However, you need to decide what you want. You say you want to buy a Suunto because it's more conservative. Then you keep asking questions about having to end your dive a bit sooner than your buddies. What exactly are you looking for in a new computer?

Paula

 

[Diver Dennis]

On group dives, you never have to go up before the folks with the Pelagic computers? (Oceanic, Aeris, Sherwood) If I am reading the specs correctly, Suunto users should have to go up before them everytime unless they are choosing to end their dives early or have their Pelagics set more conservatively.

I am almost always the last out of the water and I'm always in the last group to surface. Remember, in group dives you are never pushing the limit, or shouldn't be. Time is the limiting factor in my group dives for folks with good SACs. Most dive ops set the time limit for dives at 45 to 60 minutes, at least in my experience. A lot will bring the whole group up when the first diver reaches 750 psi or so. So Suunto is no different than other computers in most situations.

 

[bergersau]

To answer the original post for this thread.

A second computer (Carried on every dive) for backup on a livaboard or similar is fine to keep you diving if the first FAILS (Dead battery, flooded, etc).

If you've had a lockout or 'bent' either computer then you shouldn't be in the water, period. The only reason you might safely ignore a bent computer is if you've made a programming type mistake you can positively account for which is directly responsible for the lockout. For example setting the wrong nitrox mix or altitude setting, or using a rich O2 deco mix the computer cannot account for. If you've been accurately logging your dives you could then keep diving on tables or your use your backup computer.

Always abide by the most conservative computer carried by a team/group. To do otherwise is asking for trouble.

 

[rockjock3]

Wow, I had no idea this would generate such response. I left my initial post purposely vague so as to invoke as little bias from each of the camps as possible and hopefully get more succinct info. Thanks for all of it. Now here is the reality of the situation:

I've already bought one computer (Aeris) and I'm having problems with it. One of the problems is the ability to download the dives which is important to me. Another is the liberal nature of the Aeris. I am beginning to believe I would like a more conservative computer initially as I get into diving. Something that theoretically keeps me a bit safer.

So since I am unhappy with the Aeris a bit, want good PC interface software, and would prefer a more conservative algorithm; I am thinking about buying a Suunto and making it my primary and moving the Aeris to backup.

I am looking into doing some dive trips that include multi-day dives. I really don't like the idea of getting in the middle of this and having my computer die. At that point it would be hard to back track and figure out where I am in terms of repetitive diving. A few of the resort dives and live-a-boards I am looking into have this 24 sit out for locked out computer rule. And I have heard a few of those "my Suunto locked out for no good reason" stories.

So I am wondering if for some reason my Suunto gets locked out on one of these trips, will the DMs allow me to continue on the Aeris? Or is that even a concern?

Oh the last point, I am one of those high tech lazy newbies that don't see a ton of value in doing the tables when the computers do that for you so much better. I know that's probably a thread ender, but again, its the reality of the situation.

I am also a newbie, but I will try to answer this from the same point of view you might be coming from.

A computer is a backup to your dive tables, not the other way around. If your are keeping track of your dive profiles then it won't matter if your computer fails as you will know where you sit with your PGs and RNT from your previous dives. If you want to buy a new computer because you are unhappy with this one then don't use this one as a backup, simply sell it or toss it.

If you buy a second computer it will never serve you as an adequate backup, in the situation you propose, unless you are wearing them both at the same time while diving. If you don't then the backup won't have any information from your previous dives and if you were tracking your previous dives using your tables and logbook then you don't have the need for the second computer.

A much cheaper backup to a dive computer is a simple pressure gauge and bottom timer. As long as you have been properly planning and tracking your dives with your tables then if your computer dies you can simply continue with a bottom timer and depth gauge because you will know where you are with PGs and RNT.

And for some out there that say they do many multi dive days on their computer then download all the information later or write it all down, out of the computer, when they get home, they deserve to sit out when their computer fries because they should have been keeping track of it all along. Start good habits now, while you (we) are new so that we don't have to learn them again later when we are too wise of a diver and think we know better.

 

[JeffG]

Well, the guys at DAN (and all other experts I know of will disagree with you on this. The fact is, we still don't know how to prevent DCI/DCS accidents all the time. There are - in fact - divers who get bent that "did nothing wrong". I believe that if you'll ask Mike F here on the board he can personnally confirm that. I cannot, but I trust the data.

Semantics...

If you are bent, it means your bodies ability to deal with the transfer of gas from your body to "outside" has been brought to a critical situation.

This can happen for a variety of reasons

1: Bad Dive techniques (too long...too deep...ascend too fast...etc etc etc)
2: A person's pre-conditions before they dive (PFO...fat...out of shape..etc etc)
3: A person's self-imposed conditions....Cold water, dehydrated...etc etc

The NDL is a cross between a mathematical model and statistics...
A dive computer is a mathematically simulation of what is going on...

None of these dehydrated, are fat, out of shape, have a PFO or even real flesh.

So did they do nothing wrong?

Everything happens for a reason. There are no "Undeserved hits".

 

[diverbrian]

Right now my "back-up" computer is at Suunto awaiting replacement because it thinks that I am 45 ft. when I am a zero ft. (what a long dive, LOL). Computers do fail. If you are doing multi-level diving and don't do any depth averaging or use the PADI's wheel (which I sometimes fit into this category), then a computer will by you more bottom time than a table based on a square profile. As Paula stated, I don't want to sit out the middle of a dive trip just because my computer failed and I have get enough inert gas out of my system to use tables.

If I am diving recreationally, I dive two different computers and stay well within the limitations on both. I can't say that the VR3 is that much more liberal than my VyTec (the back-up). The VR3 algorithm definitely pushes deeper stops though. The VyTec likes it's stops to be shallower and is far more touchy about fast ascents and surface intervals. But as I said, I stay within the limitations on both and I am pretty happy with that arrangement when recreational diving.

 

[lamont]

If I am diving recreationally, I dive two different computers and stay well within the limitations on both. I can't say that the VR3 is that much more liberal than my VyTec (the back-up). The VR3 algorithm definitely pushes deeper stops though. The VyTec likes it's stops to be shallower and is far more touchy about fast ascents and surface intervals. But as I said, I stay within the limitations on both and I am pretty happy with that arrangement when recreational diving.

You dive both a VR3 and a Vytec for recreational diving? Can we trade disposable incomes?

Lotta bling on your wrist there...

 

[JeffG]

how are people locking out their computers? didn't they notice the little flashing lights telling them not to ascend above 10 fsw?

Some of the time its stupid stuff. I was diving my Oceanic Versa 200 (I think that was the model). Anyways...If you did one dive on nitrox setting, and then did another dive without re-setting the "new" O2 setting. It would default to 50% O2. I was sitting at 85 ft with this thing blinking, whining...etc etc and I was doing a second dive of my twin 130's that had 32%.

True, it was user error....but I just ignored what my computer was saying (which is not for everyone) and continued with my dive.

People can either understand what is going on, or they can dive their computers blind.