V Planner Deco Conservatism

[Bismark]

I am not that heavy in Ratio Deco...it seems to only apply with standard Trimix gases, or at least that is what I have read about. Is there a good "ratio deco" for dummies out there. I have a technical background, but any discussions I have read focus on standard mixes to be an entry condition for successful ratio deco...which I know is not true.

You are wrong. RD is designed to work only with standard mixes.

Do you really want a RD for dummies?..............

 

[mark gottfried]

I would like to venture into this discussion with couple of suggestions. RD is one of decompression strategies and as such works within certain parameters i.e. using standard gases, set points, curve shaping, deep stops, oxygen window and a gradient. Overall resulting in exponential shape of decompression. It of course also covers recreational parameters (with 32% as a standard gas).

For detailed information you can visit UTD website (apparently I don't have enough posts here to post an URL, but I'm sure somebody can post the actual address) where you find a forum with RD discussions but more importantly a Ratio Deco online class available to everybody.

 

[Bismark]

I would like to venture into this discussion with couple of suggestions. RD is one of decompression strategies and as such works within certain parameters i.e. using standard gases, set points, curve shaping, deep stops, oxygen window and a gradient. Overall resulting in exponential shape of decompression. It of course also covers recreational parameters (with 32% as a standard gas).

For detailed information you can visit UTD website (apparently I don't have enough posts here to post an URL, but I'm sure somebody can post the actual address) where you find a forum with RD discussions but more importantly a Ratio Deco online class available to everybody.

Hi Mark,

I think you mean Unified Team Diving

 

[MXGratefulDiver]

I have a good friend whom I dive with who uses R/D exclusively.

Whenever we are on deco together at the 20 ft stop, he signals to me "what does your computer [DiveRite NiTek HE] say?"

And I signal back to him "the computer says XX minutes here."

After the dive, he always comments to the effect that R/D and my computer give virtually the same results.

I find that to be fascinating, and also a great confirmation for both.

Not my experience at all ... the Nitek He uses an algorithm that wants ALL of your deco above 30 feet.

I use RD ... but wear a computer as a "sanity check". I started with a Nitek He, and quickly realized how incompatible with RD it actually was ... I bent it on every dive if I stuck to the RD schedule, because the amount of deco I did between 70 and 30 feet were not counted in the Nitek deco schedule. I sold the Nitek and got a Cochran EMC20H. Did one dive with it, and decided I didn't like the way it worked. Sold it and got a Tec2G ... put it in gauge mode, and relied strictly on that for a while. Then I got a Liquivision X1 ... running VPM. Put in on +3 conservatism and it tracks with RD nicely on most (but not all) dives. Caveat ... I haven't yet taken it below 200 fsw ... it'll be interesting to see how it tracks on deeper dives.

... Bob (Grateful Diver)

 

[rjack321]

Not my experience at all ... the Nitek He uses an algorithm that wants ALL of your deco above 30 feet.

That's the difference between your experience in like "water", vs. just with electrons

 

[scubadada]

Back to the OP please. 130 ft for 20 minutes, about twice allowed for the NDL. USN tables would give deco at 10 ft for 4 minutes. I'm pretty sure my Oceanic Pro Plus 2 and back up Dive Rite Nitek Duo would also give me a reasonable deco time at 10 ft. What am I missing here with a deco time of almost 24 minutes starting at 60 ft? This is hardly a hard core tech dive, we all overstay our limits within recreational depth and pay small deco obligations. Do you have some outcomes data I'm unaware of or is it just ultra-conservatism?

I'll save you all the time for some of your pompous, arrogant, condescending criticism, I'm a moron recreational diver.

Good diving, Craig

 

[scubadada]

Back to the OP please. 130 ft for 20 minutes, about twice allowed for the NDL. USN tables would give deco at 10 ft for 4 minutes. I'm pretty sure my Oceanic Pro Plus 2 and back up Dive Rite Nitek Duo would also give me a reasonable deco time at 10 ft. What am I missing here with a deco time of almost 24 minutes starting at 60 ft? This is hardly a hard core tech dive, we all overstay our limits within recreational depth and pay small deco obligations. Do you have some outcomes data I'm unaware of or is it just ultra-conservatism?

I'll save you all the time for some of your pompous, arrogant, condescending criticism, I'm a moron recreational diver.

Good diving, Craig

Sorry, I forgot to state my own conservative activity. My Dive Rite Nitek Duo is considerably more conservative than my Oceanic Pro Plus 2. I always clear the deco on my Dive Rite prior to surfacing. That often gives me a clear Oceanic plus several more minutes for a "safety stop"

 

[jtivat]

Does this make sense to anyone? Or is anyone seeing the same thing?
I think that the V Planner is probably more useful on longer/deeper dives, with mix, and a deco gas or two, where the computer would give you better deco profiles than using the tables.

Any thoughts?

No it does not make sense to me. I would use 28% and deco on 100% with a +3 on V-Planner and only do 9 minutes of deco.

 

[Sabado]

Thanks...that is exactly what I was looking for. I will try that profile and see the deco it gives me. It probably will not match your 9 minute plan. Since you are using the v planner conservatism of +3, you don't have custom adjustments to your algorithm...I'll let you know what I get.

 

[jtivat]

Thanks...that is exactly what I was looking for. I will try that profile and see the deco it gives me. It probably will not match your 9 minute plan. Since you are using the v planner conservatism of +3, you don't have custom adjustments to your algorithm...I'll let you know what I get.

The water I dive is 38 degrees and I have been bent so I always use +3.