What is Ratio Deco?

[PfcAJ]

So then the question becomes "would you do this deco if you weren't on a OMG TRUK LAGOON trip"?

 

[kr2y5]

Just wondering, why anybody would use ratio deco at the time of dive planning? It sounds like insisting on eating with plastic fork on a paper plate, when proper utensils are available...

 

[LiteHedded]

Just wondering, why anybody would use ratio deco at the time of dive planning? It sounds like insisting on eating with plastic fork on a paper plate, when proper utensils are available...

gue ratio deco works pretty well in the 30 or so minute bottom time range.
so cobbling together a schedule on a boat on the way to a site works pretty well.

 

[CptTightPants21]

Just wondering, why anybody would use ratio deco at the time of dive planning? It sounds like insisting on eating with plastic fork on a paper plate, when proper utensils are available...

It is something that can be used on the fly. What if all of your computers fail (maybe one floods and you lose one)? What if you miss your depth or over stay your planned dive time? It is a way for a diver to plan a deco schedule on the fly with nothing more than his brain.

 

[PfcAJ]

Just wondering, why anybody would use ratio deco at the time of dive planning? It sounds like insisting on eating with plastic fork on a paper plate, when proper utensils are available...

Its a good thing to have in your back pocket. Maybe you planned for 30 at 150, but it was really 20 at 160. Wat do? Or you planned for 20 at 250, but you saw something cool at 230 and spent 20mins there instead. With RD, you can quickly adjust your deco schedule either in water or on the boat.

 

[kr2y5]

gue ratio deco works pretty well in the 30 or so minute bottom time range.
so cobbling together a schedule on a boat on the way to a site works pretty well.

It is something that can be used on the fly. What if all of your computers fail (maybe one floods and you lose one)? What if you miss your depth or over stay your planned dive time? It is a way for a diver to plan a deco schedule on the fly with nothing more than his brain.

Its a good thing to have in your back pocket. Maybe you planned for 30 at 150, but it was really 20 at 160. Wat do? Or you planned for 20 at 250, but you saw something cool at 230 and spent 20mins there instead. With RD, you can quickly adjust your deco schedule either in water or on the boat.

Thanks. Do you find it easier to do the on-the-fly calculations in the water if you previously planned the dive with ratio deco before entering the water? I mean this, as compared to using software to plan, and then only reverting to ratio deco if you ended up deviating from your plan while in the water. I understand that it makes a lot of sense to do the math and stick to it, if you want to be better prepared to make real-time adjustments, especially if you slightly deviate from the plan on a regular basis.

 

[PfcAJ]

I typically look at the software first. If the dive is shorter or longer, or a little shallower or deeper, I'll make RD adjustments.

I COULD (and often do) print tables, and I COULD pull the out and look at them, sure. But if the table says the same thing RD says and the dive is straight forward, I'll just do a quick RD based ascent and be done with it.

 

[kr2y5]

I typically look at the software first. If the dive is shorter or longer, or a little shallower or deeper, I'll make RD adjustments.

I COULD (and often do) print tables, and I COULD pull the out and look at them, sure. But if the table says the same thing RD says and the dive is straight forward, I'll just do a quick RD based ascent and be done with it.

Got it, thanks. I am surprised that software developers have not yet offered a simple feature: "Ratio Deco agrees with Buhlmann ZHLC on this profile to within +/- 10 minutes and +/- 50 feet", just as a basic sanity check.

 

[CptTightPants21]

Got it, thanks. I am surprised that software developers have not yet offered a simple feature: "Ratio Deco agrees with Buhlmann ZHLC on this profile to within +/- 10 minutes and +/- 50 feet", just as a basic sanity check.

That would be a cool feature and I wonder if GUE's deco planning software does it.

I am not sure if it was mentioned in a previous post, but Ratio Deco is based on patterns that can be found in decompression schedules. I don't know the specifics, but they essentially averaged out thousands of profiles and patterns and used them to make a shortcut to calculating decompression.

 

[LiteHedded]

That would be a cool feature and I wonder if GUE's deco planning software does it.

I am not sure if it was mentioned in a previous post, but Ratio Deco is based on patterns that can be found in decompression schedules. I don't know the specifics, but they essentially averaged out thousands of profiles and patterns and used them to make a shortcut to calculating decompression.

gue's planning software was written in the stone age so I wouldn't go looking for cool features