Quote: (Originally Posted by Simon Ciantar)
I am TDI Nitrox , TDI Trimix , TDI CCR Diver,and CMAS two star instructor since 1994 I have been diving for three years with Trimix OC to 60m + dives.
Simon,
Your profile doesn't state what level of diving you do, so I hope it is understandable for what I said earlier...
You would be surprised, but I personally know one trimix instructor who has no idea about decompression. He can't explain the difference between VPM, RGBM and GF for example.
So having a card says nothing to me, but the least we could do is we shouldn't be giving deco information for someone who doesn't have the "training". Right ?
Anyway, enough links have been given for you to do your own reading. But basically in layman's terms, GF is intended to add some conservatism to the straight Buhlmann algorithm by allowing you to adjust where you want to start your deep stops, and how much you want to stretch your shallow stops.
GF-low dictates the deep stops, the smaller the value (i.e. 10, 20) will start the first stop deeper than what you usually experienced with Proplanner.
GF-high dictates the shallow stops, the smaller the value (i.e. 85, 70) will lengthen the last few stops.
So GF of 10/90 will start the stops quite early, and you will be making 1-min stop every 3m until your last stop (3 or 6m) when you will stay just a bit longer than normal Buhlmann.
By setting the GF to 100/100, you will the straight Buhlmann algorithm with NO conservatism.
The conservatism used in Proplanner is DSF (deep safety factor) which modified your deepest depth by a percentage fraction in the algorithm to load the theoretical tissues a bit more than actual.