New Shearwater Dive Modes.

[Pavao]

The three gas option is a nice option as I program them for 21%, 32%, and 36%. Once I splashed but forgot that on the later dive I was using air and not 32%. So just switched on the fly.

Well, sorry to say but you’re not using your computer properly. When you program those 3 gasses and go do a dive, the computer is calculating your decompression based on having those 3 gasses with you on the dive and that you will make 2 gas switches.

What you were trying to say is that shearwater computers lets you edit gasses while underwater, that has always been an option, in fact you don’t need to pre-program them, you can just create one underwater. But given these new features I’m not sure that is available in modes like that.

And lastly, to the point of the thread, you could always have done that in the OC tec mode, so, again, what’s the point of this mode?

 

[Pavao]

Right in the screenshot of the manual in your OP: "Designed for introductory technical diving activities including diving involving planned decompression."

”Serious recreational diver” wtf is that? And a 2 gas switch is not an introductory technical dive.

But still, what I’m trying to understand, is, the need for this differentiation from the OC tec mode.

If you or anyone would like to give a dive example where this mode makes sense…

 

[Hppyfam]

You are already coming into this close-minded to any argument people put for the modes. But to give an example of why it can be used. As an instructor I have OC tec, Nitrox and Air mode setup. OC Tec I use when teaching/ diving deco dives. Nitrox when teaching AoW/ any specialties within the recreational realm, and air for when teaching OW. I enjoy being able to set up all three modes to be customized for the information I need for those specific situations. Is this a fairly niche use case, sure.. but shearwater added the functions so why not use them.

 

[lexvil]

Some people are weirdly adverse to any change.

 

[Tracy]

Let’s preface this by saying I’ve been diving Shearwater computers for over 13 years, and I don’t think there are better dive computers.

The new Perdix 2 has 3 new dive modes that makes me scratch my head, “Air mode”, “Nitrox single gas” and “Nitrox 3 gas”, this is the sort of thing we see on just about any dive computer manufacturer out there, I’d call these recreational “wanna be” technical dive computers, they’re just regular computers with 3 gas capability but sucks at decompression diving.

I thought the industry was done with this “Air mode” thing too, pretty much everyone just understood that leaving the mix at 21% is “Air mode”, but then here comes Shearwater with it.

This being present anywhere else I wouldn’t question it, but if Shearwater does it, makes me pause to think, have I not understood this whole thing? It’s like when they started supplying surgical tubing for straps for their computers, I understood bungee cord to be far superior than surgical tubing, but if shearwater was sending out their computers with surgical tubing, I went, woah, what do they know about them that I don’t? Why not supply the computers with bungee? I mean, it’s shearwater, they know what they’re doing, right? It’s not engineers with little dive experience producing subpar dive gear pushed to the market by the marteking department of a large corporation manufacturer.
But it isn’t, bungee is far superior than surgical tubing.

So, to the dive modes, I’ve typed way more than I like too already, let me ask just the “Nitrox 3 gas” mode for now, I’m having a hard time understanding the real use of such a mode, it’s for recreational diving, aka, no deco. But let’s not be too strict, some recreational divers do go into deco, they call it “light deco” dives, or something like that. And that is deco done on back gas.
So, say such a diver now decided that the “light deco” they do warrants bringing a 2nd gas mix to accelerate the decompression, I mean, I get to this point in typing this and I’m already finding a hard time continuing and not describe a tech dive.
And the mode is designed to allow 3 gasses, in what agency/training are divers trained to use 3 gasses in which it doesn’t fall into the tech diving realm?
Even on the tech dive training, how many agencies/courses start students with 2 gas switches right at the entry level?
And what agency/training gives RECREATIONAL divers access to mixes higher than 40%? This question is also important when consider a dive requiring 3 gasses, which none are higher than 40% O2

So, please educate me and help me understand the real practical application of such a mode. In doing so, please provide an example dive with the depth, time and gases, that doesn’t fall into the tech diving category of course. And if managed to do so, please also contrast that with just using the “OC Tec” mode.

What’s next, future versions gonna lock divers out too?
View attachment 816727

I use three gas nitrox mode or CC mode. I like the big numbers and format that is in recreational mode so I just use the three gas mode. It works great. OC tec is only useful to me for deeper OC trimix diving which is something I haven't done in many years.
As to the surgical tubing, I like it more than bungee. It doesn't last as long, but the computer also doesn't move on your sleeve. Bungee slips around.

 

[Pavao]

I use three gas nitrox mode or CC mode. I like the big numbers and format that is in recreational mode so I just use the three gas mode. It works great. OC tec is only useful to me for deeper OC trimix diving which is something I haven't done in many years.
As to the surgical tubing, I like it more than bungee. It doesn't last as long, but the computer also doesn't move on your sleeve. Bungee slips around.

Thanks for the answer Tracy. That is a valid reason to go from OC tec to Rec mode.
Wouldn’t the OC Rec mode, as opposed to the Nitox 3 gas mode do the same for you?

Sorry, can’t relate to your issues with bungee, not in my arm at least. I’m aware of it slipping around in other applications, like hose retainer, light retainer…

 

[jborg]

Wouldn’t the OC Rec mode, as opposed to the Nitox 3 gas mode do the same for you?

"3 Gas Nitrox" is just the new name for what used to be called "OC Rec".

The new modes are Air and Nitrox which are just simplifications for the divers who only use air or only use one nitrox mix.

 

[Tracy]

Thanks for the answer Tracy. That is a valid reason to go from OC tec to Rec mode.
Wouldn’t the OC Rec mode, as opposed to the Nitox 3 gas mode do the same for you?

Sorry, can’t relate to your issues with bungee, not in my arm at least. I’m aware of it slipping around in other applications, like hose retainer, light retainer…

3 gas NX is an option in Rec mode

I use rec mode for OC and CC mode for CC.
I actually really like the peregrine for OC tech diving. For me, it offers the same thing as the perdix for near half the money.

 

[ReefHound]

Well, sorry to say but you’re not using your computer properly. When you program those 3 gasses and go do a dive, the computer is calculating your decompression based on having those 3 gasses with you on the dive and that you will make 2 gas switches.

How exactly is it going to do that when it doesn't know WHEN or IF you will switch?

 

[hedonist222]

How exactly is it going to do that when it doesn't know WHEN or IF you will switch?

I think the computer prompts you to change the tank to the tank with the gas mixture based on your depth - it selects from the 3 tanks it thinks you have.