Attenuated RGBM in Suunto Vytec

[EANx]

SUUNTO Vytec has the ability to set the RGBM model to 50% effect, thereby making the model less conservative. This is for "experienced divers who are less prone to decomression illnes and who are willing to accept a greater risk", according to the Vytec intstruction manual.

Question 1)
But just HOW MUCH greater is the risk, and how much time in minutes at various depths will a 50% RGBM setting give?

Where specifically can I find more quantitative data on this?







Question 2)
In the simulation mode, how do I plan a dive with a switch to a deco gas of higher oxygen percentage? I know how to do it during diving (pressing the Mode button until you can toggle between MIX 1,2 and 3), but in the simulation mode it keeps throwing me out of the simulated dive and back to the main screen... Obviously I'd like to plan for which deco gas gives me the optimal deco time for a specific SAC rate etc.

 

[jplacson]

I have a Vytec as well... and I think I know why they didn't put a planning feature with the gas-switching included... it's to keep OW divers from trying out a deco dive.

Honestly, since the advent of dive computers, OW divers have become more relaxed and less dependent on tables... this is a bad thing since if your computer fails at depth, you're screwed.

And I think any diver trained for deco dives won't want to use a built-in dive planner anyway. It's always better to plan a deco dive on the surface, and just use the Vytec as a redundant device during the dive to keep you 'on track'.

From what I've heard, the RGBM model of the Vytec isn't a true RGBM system anyway... so I only use it like I would a Vyper... the only reason I got the Vytec over the Vyper (the Vyper is all I need actually) is because my LDS was on sale with just the Vytec, and I got it for $60 more than the Vyper.

 

[MechDiver]

EANx once bubbled...
SUUNTO Vytec has the ability to set the RGBM model to 50% effect, thereby making the model less conservative. This is for "experienced divers who are less prone to decomression illnes and who are willing to accept a greater risk", according to the Vytec intstruction manual.

Question 1)
But just HOW MUCH greater is the risk, and how much time in minutes at various depths will a 50% RGBM setting give?

You can easily plan a dive with the simulator to see what the difference in BT is. The Vytec is a very conservative computer, even with the 50% factor setting.

As for your second question, it shows you really need to take a class in deco diving. It's not something you just jump into with a half-butt computer thats not made to do it anyway.

MD

 

[jplacson]

MechDiver, I agree... even though the Vytec clearly says it's a deco computer... it also states in the manual that it is not to be used for technical or commercial diving.

I believe that the RGBM model used by Suunto isn't meant for tech divers... it's meant as a safety feature for rec divers who accidentally violate their no-deco limits... then the Suunto will help you ascend safely.

It isn't meant for intentional deco dives... the thing freaks out even in SIM mode... it beeps when you exceed your limits, then beeps to tell you to ascend to a certain depth. Then gives you a mandatory deco stop ceiling, then when that's done, it gives you a mandatory safety stop... then extended SIT.

As for the gas-switching capabilities, I really don't know how freaked the Vytec will be under real deco situations as I'm not a tech diver.

I am curious as well on how the Vytec performs as a computer during a deco dive, with gas-switching... not just in gauge mode or as a bottom-timer... I'd like to know if it works DECENTLY as a computer.

 

[Genesis]

It isn't meant for intentional deco dives... the thing freaks out even in SIM mode... it beeps when you exceed your limits, then beeps to tell you to ascend to a certain depth. Then gives you a mandatory deco stop ceiling, then when that's done, it gives you a mandatory safety stop... then extended SIT.

As for the gas-switching capabilities, I really don't know how freaked the Vytec will be under real deco situations as I'm not a tech diver.

I am curious as well on how the Vytec performs as a computer during a deco dive, with gas-switching... not just in gauge mode or as a bottom-timer... I'd like to know if it works DECENTLY as a computer.

First, it doesn't give you a mandatory place to ascend to. You're misreading the computer's display.

Actually, the Vytec's "total deco obligation" tracks things pretty well. Its biggest problem is that it doesn't believe (much) in deep stops.....

When I'm planning to do a deco dive, I use VPlanner for that. But I still take the Vytec for backup, and use its gas-switching capability.

The thing is that it will give you an ABSOLUTE ceiling, but you'd be foolish to go there and sit. Instead, follow a proper curve; you will be within the offgassing range for the Suunto, and it will indeed give you proper credit as you ascend.

It is actually less conservative than VPM-B set to +2 conservatism in that the computer will clear before the tables on what is effectively a square profile dive!

Its not a bad deco computer as a backup, but provides NO planning guidance. The thing to realize about that is that such an omission is really fairly smart from Suunto's point of view - consider this - while the computer could give you a time requirement, what it can't do (on its own) is give you a GAS requirement, and if you don't know how to compute that, well, running out of gas on a deco hang could be pretty ugly.

 

[jplacson]

Genesis, sorry... that's actually what I meant, a mandatory STOP... with a depth ceiling (obviously a ceiling doesn't mean that that's the only place you can stay at)

Like I said, I'm not a deco diver yet, so I just play with the regular dive sim.

But it's nice to know that the Vytec isn't just some fruitcake computer and can actually be used as a back-up COMPUTER (not just a gauge or BT)

Thanks Genesis!

 

[Genesis]

I'd consider it a VERY bad idea to use it as a SOLE deco tool however....

 

[jplacson]

:lol: ya... that would be dumb.

I'm just glad to know that once I take my tech diving classes, I can actually use the Vytec as a computer... not just the usual "Gauge Mode"

I mean, it's kinda nice to have a '2nd opinion' of some sorts.

 

[Genesis]

It doesn't do He-based gasses however, so there, it is indeed just a glorified bottom timer