Info Two New Dive Computers from Scubapro for 23! LUNA 2.0 (with & without Air Integration with GF) with aggressive pricing

[dmaziuk]

What I don't get in all these debates is: if you're bent, what do you care about what the computer does? I'd be worried about getting to the nearest chamber, myself, but maybe that's just me.

And if you are not bent, then why does your computer believes you are?

Spoiler

The following is the actual transcript of a Word Perfect Customer Support employee, transcribed from a recording monitoring the customer care department. The Help Desk employee was fired, and is currently suing the Word Perfect organization for "Termination without Cause"!

"Ridge Hall computer assistance; may I help you?" "Yes, well, I'm having trouble with WordPerfect." "What sort of trouble?" "Well, I was just typing along, and all of a sudden the words went away." "Went away?" "They disappeared." "Hmm. So what does your screen look like now?" "Nothing." "Nothing?" "It's blank; it won't accept anything when I type." "Are you still in WordPerfect, or did you get out?" "How do I tell?" "Can you see the C: prompt on the screen?" "What's a sea-prompt?" "Never mind, can you move your cursor around the screen?" "There isn't any cursor: I told you, it won't accept anything I type." "Does your monitor have a power indicator? "What's a monitor? "It's the thing with the screen on it that looks like a TV. Does it have a little light that tells you when it's on?" "I don't know." "Well, then look on the back of the monitor and find where the power cord goes into it. Can you see that?" "Yes, I think so. "Great. Follow the cord to the plug, and tell me if it's plugged into the wall." "Yes, it is." "When you were behind the monitor, did you notice that there were two cables plugged into the back of it, not just one?" "No." "Well, there are. I need you to look back there again and find the other cable." "Okay, here it is." "Follow it for me, and tell me if it's plugged securely into the back of your computer." "I can't reach." "Uh huh. Well, can you see if it is?" "No." "Even if you maybe put your knee on something and lean way over?" "Oh, it's not because I don't have the right angle - it's because it's dark." "Dark?" "Yes -the office light is off, and the only light I have is coming in from the window." "Well, turn on the office light then." "I can't." "No? Why not?" "Because there's a power failure." "A power... A power failure? Aha, Okay, we've got it licked now. Do you still have the boxes and manuals and packing stuff your computer came in?" "Well, yes, I keep them in the closet. "Good. Go get them, and unplug your system and pack it up just like it was when you got it. Then take it back to the store you bought it from." "Really? Is it that bad?" "Yes, I'm afraid it is." "Well, all right then, I suppose. What do I tell them?" "Tell them you're too ******* stupid to own a computer".

 

[Wibble]

What I don't get in all these debates is: if you're bent, what do you care about what the computer does? I'd be worried about getting to the nearest chamber, myself, but maybe that's just me.

And if you are not bent, then why does your computer believes you are?

You're not bent.

For example if your computer has calculated that you've an additional 3 minutes of decompression and you surface, the reality is that your surface GF (just assume Buhlmann+GF) is a mere 6 more than your target GF-Hi.

Example: you're running GF50:80 on a typical deco dive where the SurfGF decreases at about 2% every minute towards the end of the dive. You could get out at SurfGF of 90 and would almost certainly not be bent -- just as ascending at SurfGF of 80 isn't a guarantee you're not bent. Even daring to ascend at SurfGF of 81% would brick the computer.

Yet you now have a dive computer that's throwing a hissy-fit because the company is covering its arse, so goes off into a sulk for two days.

Or just buy a proper computer in the first place.

 

[dmaziuk]

Example: you're running GF50:80 on a typical deco dive where the SurfGF decreases at about 2% every minute towards the end of the dive. You could get out at SurfGF of 90 and would almost certainly not be bent -- just as ascending at SurfGF of 80 isn't a guarantee you're not bent. Even daring to ascend at SurfGF of 81% would brick the computer.

So basically you were planing to surface with SurfGF of 90 and because of that you preset your gradient factors to 50:80 -- is that the reasoning here?

 

[Wibble]

So basically you were planing to surface with SurfGF of 90 and because of that you preset your gradient factors to 50:80 -- is that the reasoning here?

You know that's not the reasoning.

The point is that those bricking-susceptible computers are overly simplistic: a violation in any calculated ceiling results in it bricking itself.


Or a real example: a bloody Suunto D9tx as a backup device always demanded additional time at deco even at its most aggressive (-2) setting than a Perdix running GF50:80. Yes, of course they're running different decompression algorithms, but bricking itself if it doesn't get it's overly cautious deco time does get on one's nerves.

 

[dmaziuk]

RGBM computers may or may not be bricking for a different reason, but the bottom line is: you pre-set your computer for your planned conservatism, you ignored your plan, and now that is the computer's fault.

Read the spoiler in my previous post again.

 

[OMyMyOHellYes]

No, it’s not.

Can you explain to me how a dive computer that no longer tracks nitrogen loading, yet still functions as a depth gauge keeps a diver safe?

If they're cheap enough, buy two. When one shows its ass, take it off and leave it in the room for a day or two to work off its butt-hurt and retrieve the other one from the suitcase to use.

(yes, I know. it's just wise assery.)

 

[Wibble]

RGBM computers may or may not be bricking for a different reason, but the bottom line is: you pre-set your computer for your planned conservatism, you ignored your plan, and now that is the computer's fault.

Read the spoiler in my previous post again.

The computer unnecessarily bricking itself is the computer's (more accurately the programmer's) fault.

Misusing a computer is the diver's fault.

 

[dmaziuk]

The computer unnecessarily bricking itself is the computer's (more accurately the programmer's) fault.

Misusing a computer is the diver's fault.

And who decides it was "unnecessary" on the particular dive: the diver doing the dive, or the programmer who wrote the firmware long time ago in Finland far, far away?

 

[Belzelbub]

The point is that those bricking-susceptible computers are overly simplistic: a violation in any calculated ceiling results in it bricking itself.

Exactly. I could somewhat understand the lockout if it was based on a violation of the most liberal setting AND if the lockout resulted in a computer that did not provide depth and time information on any subsequent dive until the lockout is done. I still wouldn't prefer a lockout, but I could understand it.

A diver may opt for a more conservative setting. Ideally, a violation of the conservatism setting should provide a warning, and then calculate a safe ascent based on the next level. A user defined conservatism setting should not equal a lockout if the dive would have resulted in no violations on another conservatism setting that is available to the diver.

And who decides it was "unnecessary" on the particular diver: the diver doing the dive, or the programmer who wrote the firmware long time ago in Finland far, far away?

I'll say the diver decides. The diver is the one that has to live with the consequences. The Finnish programmer will not have to visit a chamber after a bad dive of a user. The programmer should be interested in providing the diver with all the information they need to dive safely. It should then be up to the diver to use that information to dive safely.

The lockout as it is doesn't appear to be aimed at increased diver safety. It appears more to be aimed at protecting the manufacturer from liability. How real that protection is seems unclear. Many manufacturers offer computers that will lockout, several others offer computers that won't lockout, or provide a way to disable the lockout.

 

[dmaziuk]

The programmer should be interested in providing the diver with all the information they need to dive safely. It should then be up to the diver to use that information to dive safely.

The lockout as it is doesn't appear to be aimed at increased diver safety. It appears more to be aimed at protecting the manufacturer from liability.

You set your M-values to 80% (*), you overshot them to 90%, as far as the model is concerned, you are over the M-values. You are bent, there is no "dive safely" from this point on.

If you want to continue diving from there, I think the vendor is entirely correct to tell you to go buy yourself a Shearwater. If it were me, I would not want you in my userbase either.

*) Not exactly since gradient factor applies to a and b coefficients rather than M-values directly.