New Shearwater Dive Modes.

[ReefHound]

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?

That's fine, then let me switch what's "on" in the water.

 

[jborg]

That's fine, then let me switch what's "on" in the water.

You can do that. You can enable or disable gases, as well as enter new gases, during the dive.

 

[Tracy]

That's fine, then let me switch what's "on" in the water.

You already can.
Generally, I just tell people to play with the computer and you will figure out how it works. You may actually want to read the manual.

 

[ReefHound]

You already can.
Generally, I just tell people to play with the computer and you will figure out how it works. You may actually want to read the manual.

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

 

[Miyaru]

@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?

• The only things a computer can sense (through it's sensors) are pressure and (for newer models) ambient light.
• The pressure is calculated to a depth shown on your display and
  • used in a decompression model to calculate (and thus predict) the NDL.
  • used in a decompression model to calculate TTS based on gasses that are set to on.
• The brightness of the display can be adjusted based on the ambient light measured.
• CCR: through a Fischer (or similar) connector, the values of the oxygen cells can be measured, which (combined with the measured pressure) shows the PO2, and with that value the TTS is calculated in a different way.

When it's about trust, the very last feature would be way more reason for discussion since the programming is still being improved.

 

[Manatee Diver]

The only things a computer can sense (through it's sensors) are pressure and (for newer models) ambient light.

I don't know about the Perdix, but the Teric has all the sensors you would expect in a smartwatch including gyro and accelerometer.

 

[Joneill]

One man's "lazy" is another man's "efficiency".

How is it efficient to leave gases that one is not using turned on when that will result in some of the displayed information being inaccurate? Versus the few seconds it takes to turn them off…. Makes zero sense to me!

 

[Joneill]

That's fine, then let me switch what's "on" in the water.

Proper predive planning should negate that need.

 

[VikingDives]

The computer assumes some level of competence when in multi gas modes. If you have the gas turned on, it assumes you will use it and bases time to surface estimates on that.
If you have three gases turned on and are only carrying one, your tts will not be accurate.

This whole thread should be people shouting this into tech divers' ears.

 

[VikingDives]

You are trying to connect a general warning with a statement specific to deco diving. The ONLY time that SRI will factor in the non-active but turned on gasses for NDL diving is when in planner mode, and you plan a dive that is too deep for the active gas. So for example if you have 32% as the active gas, and 21% turned on; and you plan a dive to 140ft. The planner will assume that you are going to switch to 21% when you hit the MOD based on 1.4 for 32%.

But during the dive it will only show the NDL for the depth you are presently at based on the gas you are currently breathing. The NDL will only change to that of the other gasses if you do a gas switch. So while below NDL, other gasses aren't really a factor.

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...