Diving Nitrox with Computers?

[jmasin]

I fully agree that best practice is just to know your plan and dive your plan. The question is, why is that 32% a more useful static parameter to stare at during the dive than 32.8m, the MOD for a 1.4 ppO2? Let's fix the discussion at 1.4 ppO2, for simplicity.

I must admit I just now fully understand your question, mostly my fault because I'm not familiar with the computer model you reference.

I don't really have an answer. I'm surprised it shows any static numbers.

The Manta shows no static numbers during a dive. It displays

Depth
Dive time
N2 based no-deco time remaining OR O2 sat time remaining depending on the limiter at the moment
an little "Nx" if you are diving enriched
a bar graph indicating the N2 or O2 loading


In setup mode you enter your PPO2 limit and mix details. I think you can enter a PPO2 max and a different PPO2 alarm, I forget.

If you do trigger an alarm the display will show the alarmed number, i.e. if you hit max depth you'll get a "TOO DEEP" flashing and depth flashing. I've hit this one time when the computer defaulted to a 50% mix and I forgot to reset it, so I got depth alarms at something like 48ft. Scared the crapola out of me until I realized what had happened.

 

[DevonDiver]

In terms of the functionality and design of the Vyper... it may be because it shares a common platform/construction with other suunto computers (vytec/helo2) that have a gas-change / multi-gas function.

If you were diving/changing between 2 or more gas mixes, then the display of what gas you were currently using becomes more critical. With the single gas Vyper, it is less essential.

 

[driebel]

I agree with DevonDiver here. In the purely recreational context of single gas dives at less than 40%, I stubbornly cling to my original opinion. However, thinking through the process of multi-mix dives, which I know only in the faintest abstract, clearly displaying the percentage O2 the computer is currently using to calculate everything is definitely the far superior indicator.

I stand much enlightened, thanks to everyone who chipped in their thoughts!

 

[watboy]

Repeating myself, but on the Vyper you can choose what the secondary display information is. If you want EANx% or PP02 or FO or temperature or time or max depth or whatever you fancy, you can toggle those displays during the dive. You also can set your PPo2 max and set an alarm if you breach it as well. The only displays you cannot change are the depth and NDL time remaining and those are the big numbers. Its much better to show PPo2 than to show MOD. And RTFM.