New Shearwater Dive Modes.

[VikingDives]

If folks are too lazy to turn off it gases that they are not using, maybe they need a new hobby? It literally only takes a few seconds to do so why would anyone want to leave a gas turned “on” if they are not carrying/using it?

It's usually just a residual from the last dive.

 

[Pavao]

Hmm, it seems by these last several posts you guys are catching on to the original point of this thread.

For those fan of these latest modes, have you tried a Suunto?

 

[ReefHound]

@ReefHound

You've had already many reactions on not trusting a computer's prediction.
Have you considered that fact that the (old) tables are based on the exact same prediction calculation?
If you don't trust the model, then what do you trust?

I'm not talking about trusting the model. That has been proven reliable through mountains of empirical testing. I'm talking about trusting that a human is going to make a series of precise steps. I guess it's a matter of degree because of course it is assumed that you don't exceed a safe ascent rate but that's quite a bit different than assuming you will perform a sequence of gas switches at precise depths.

 

[ReefHound]

Proper predive planning should negate that need.

If we could all be as perfect as you then you wouldn't be so amazing.

 

[Tracy]

Refer to the image of the manual in post 1, it says not switchable underwater in single gas mode.

why would it be? It is single gas mode, what would you switch it to if you only have a single gas?

 

[Manatee Diver]

So, this is sort of right, but if you had been doing a deco dive (this happened to me) and you last gas was nitrox 50....

Then you jump in to teach with a cylinder of air, and you are tooling around at 55 feet for 10 ish minutes before you notice that you're still set to N50 and not .21, you may feel stupid. Even if you make the gas switch on your computer, you've screwed your calculations, at least as they relate to your computer...

That is why checking the active gas should be part of any predive checks.

But I've never accidentally left my oxygen active and it screams at me at around 30ft with HIGH PPO2... yeah never...

 

[VikingDives]

That is why checking the active gas should be part of any predive checks.

But I've never accidentally left my oxygen active and it screams at me at around 30ft with HIGH PPO2... yeah never...

I agree it shouldn't happen, but I'm not the only one it's happened to.

I'm pretty sure it won't happen again though

 

[L13]

I'm not talking about trusting the model. That has been proven reliable through mountains of empirical testing. I'm talking about trusting that a human is going to make a series of precise steps. I guess it's a matter of degree because of course it is assumed that you don't exceed a safe ascent rate but that's quite a bit different than assuming you will perform a sequence of gas switches at precise depths.

In order to apply the model, it must assume something! All it has, is what it has measured so far, what you have told it in the settings, and what you are supposed to do, if you are following the model. What level of imperfection would you like it to assume? At that level, which of the infinite possible variations of behavior should it assume?

The tables assumed correct behavior throughout the dive. The dive computer is slightly better. It uses actual measurements of the dive till present, only assuming correct behavior in the future, and that you have not lied to it in the settings.

 

[Joneill]

If we could all be as perfect as you then you wouldn't be so amazing.

I didn’t say I was perfect, but I figured folks diving multiple gases would square all that away before splashing as part of a checklist. I’m a single gas diver, but still always make sure the gas I’m diving is the only one turned on.

 

[inquis]

when that will result in some of the displayed information being inaccurate?

The OP has not stated they are doing deco dives. Nothing displayed is inaccurate when multiple gases are turned on until there is a deco obligation.

Heck, even if they go into light deco on a deeper rec dive, the prediction error between an assumed 36% and actually using 32% for a 5 minute obligation is hardly worth talking about.