Decisions on a Dive Computer

[Wibble]

Must have been frustrating, especially because this wasn't explained in the manual... apparently.

Beginning OW students are taught the most important thing about using a DC is to read the manual so they know how it works. This is good advice for experienced divers also.

Oh, and I'm still willing to buy that D9 from you, if it's just sitting in a box. It's very similar to my D6, an I've already read the manual. So I won't have the same problems with it that you've encountered.

Are you a lawyer as well as patronising?

You try finding the stupid 'lockout' clause tucked away in the how to do the strap up and other useless crap that the manual contains. Seriously, do try to find that lockout info.

Now compare that Suunto junk with a Shearwater. The UI is pretty obvious and there’s no pathetic foibles lurking. Have only ever referred to a Shearwater manual a couple of times, such as looking up the GF99 info. All the rest is bleeding obvious, even after they’ve added all the CCR extensions to the menus, even adding AI, etc.

 

[Belzelbub]

You're totally missing the point.

People complain that Suunto's do not "allow" them to stay under long enough. My point was that dive computers do not "allow" or "disallow" anything. They simply provide advice.

The idea that a dive computer says "your time is up!" and you must obey it is ridiculous. We are free to make our own decisions. So if you use a Suunto (or any dive computer) in "dive mode", it will give you its best advice of when you should end your dive. If you want to ignore that advice, you can stay longer. And if you want to ignore your computer's advice, you may as well put it in "gauge mode" so it won't bother you.

I apologize if the point I was making with the original "gauge mode" post was too subtle.

Technically, you are correct. The dive computer doesn’t prevent the diver from diving anymore. Instead, it applies a rather long period where it won’t track your diving anymore due to a violation, or apparently for switching modes. A dive computer is a tool, and at the point where it’s gauge mode only, it’s not nearly as useful as it could be.

Contrast that with a dive computer that won’t lock you out. No matter how much you ignore it, it will continue to guide you on any subsequent dives you may do.

May or may not help you, but at least it will still function at 100%. Different approaches by different manufacturers. One assumes the diver is competent and responsible for making their own decisions. One does not.

 

[yle]

Try £50/€60/$70 in a dive shop!!!

The battery is pretty standard for £5 off Amazon etc. Need the screwdriver

I bought the screwdriver, one with eight small T-bits (including the one that fits the D6, and I think it fits the D9 also), for about $7. Already used it a few times on the D6's. Certainly pays for itself just using it for one battery change.

And yeah... $70 for a battery change is just plain silly.

 

[yle]

Are you a lawyer as well as patronising?

You try finding the stupid 'lockout' clause tucked away in the how to do the strap up and other useless crap that the manual contains. Seriously, do try to find that lockout info.

My apologies, you're right. I got a little too carried away with my defense of Suunto. I haven't looked through the manual to see if they explain the lockout issue, but I do believe you that if it is in the manual you'd probably have to read through 143 pages to find it.

 

[yle]

Technically, you are correct. The dive computer doesn’t prevent the diver from diving anymore. Instead, it applies a rather long period where it won’t track your diving anymore due to a violation, or apparently for switching modes. A dive computer is a tool, and at the point where it’s gauge mode only, it’s not nearly as useful as it could be.

Contrast that with a dive computer that won’t lock you out. No matter how much you ignore it, it will continue to guide you on any subsequent dives you may do.

May or may not help you, but at least it will still function at 100%. Different approaches by different manufacturers. One assumes the diver is competent and responsible for making their own decisions. One does not.

Are you suggesting there are recreational dive computers that will...

allow a recreational diver to incur an emergency deco obligation,

surface without clearing the obligation,

and then still track that diver's NDL on a second dive a short while later?

Because that is the scenario under which a Suunto DC will "lock out", only if the diver ignores the computer's advice that they make a required stop.

If there is such a recreational DC that would track NDL for a second dive after a missed deco obligation on the first dive, please let me know. I find the possibility fascinating.

Until then, you can keep trying to convince me that my Suunto D4 doesn't work properly, but it's way ahead of you: in the past 13 years it has never quit on me, never restricted my diving, and I've never had a DCS hit. You might want a DC that does fancier stuff, but this is all I need.

 

[KenGordon]

If there is such a recreational DC that would track NDL for a second dive after a missed deco obligation on the first dive, please let me know. I find the possibility fascinating.

That is what the Shearwaters will do. If you are above the stop it just goes a bit red. It can carry on because the simple dissolved gas model will still “work” once the compartments that crossed the line come back below it. Whether that excessive deco stress matters or not later is not part of the model.

The one, not really ‘recreational’, use for this behaviour for me is when bailing out of CCR. For an aggressive ascent I have a choice of 49/99 and 90/90, I would like 99/99. Shearwater could fix my case. GF99 sort of covers it.

The trouble is that SB posters don’t really take a mass market, population based view. What stops a mass of divers overstaying, getting into some deco, skipping it or failing to notice and a few getting bent? The POV is all ME and I know what I am doing, allegedly.

 

[KenGordon]

May or may not help you, but at least it will still function at 100%. Different approaches by different manufacturers. One assumes the diver is competent and responsible for making their own decisions. One does not.

See.

Function at 100% hmmm…

Competent? Just missed some stops and wants to dive again?
Responsible? No kids, no buddy, no other divers having their day spoilt by an early return or visit from a helicopter?

 

[Sunn]

(...)

Also I am only recently open water certified and I am not doing any kind of advanced diving currently. Advanced open water maybe in my future at some point, but that maybe a while. (...)

As beginner, first dive, then get experience and after.... a long time after, when you'll be an experienced diver, then think about your equipment...

Don't be a victim of the marketing ! That's not the quality or price of your equipment that will help to make you a better diver, but only your skills and experience.

 

[Wibble]

As beginner, first dive, then get experience and after.... a long time after, when you'll be an experienced diver, then think about your equipment...

Don't be a victim of the marketing ! That's not the quality or price of your equipment that will help to make you a better diver, but only your skills and experience.

This neatly sums up my experience with Suunto.

I bought the D9tx when I was a novice, swayed by the "tec" credentials - literally lusted after it and swallowed their marketing guff hook, line and sinker. I really was their target market; knew nothing, dead keen, looking to my "tec" ambitions, even respected DiveMASTERS who wore such symbols of competence...

Only after I gained the experience with a few hundred dives under my wing, trimix, accelerated deco, do you then really learn of the Suunto's severe shortcomings. That I was using it as a backup to my Shearwater Perdix simply exacerbated it's recreational-oriented features.

As a "tec" computer it's thoroughly useless. It's illegible; horrendously difficult to use; has ridiculous lockouts (including having to ascend above the ceiling to change gasses - 100% won't switch until 5m); has a mass of overcautious nonsense; and the compass has never reliably worked.

As a recreational computer used when straying into occasional decompression it's OK. It's not great, just OK.

As a wristwatch it's good.

 

[Belzelbub]

Are you suggesting there are recreational dive computers that will...

allow a recreational diver to incur an emergency deco obligation,

surface without clearing the obligation,

and then still track that diver's NDL on a second dive a short while later?

Because that is the scenario under which a Suunto DC will "lock out", only if the diver ignores the computer's advice that they make a required stop.

If there is such a recreational DC that would track NDL for a second dive after a missed deco obligation on the first dive, please let me know. I find the possibility fascinating.

Yes. I am saying that. The Shearwater Peregrine will not lock you out after missing a deco stop. All of the Shearwater line behaves this way, but only the Peregrine is what I would call a recreational DC.

Like I said, two schools of thought on this. One that says, “You broke a rule. I’m not talking to you for X hours. You are on your own.” Another that says, “You broke a rule. However, I’ll still guide you should you continue to break rules.”

Neither is advocating omitting any required stops.