Free VPM Deco Software

[Lost Yooper]

To whom may be interested,

I just found out that Ross Hemingway has put out a VPM (Varying Permeabilty Model) decompression planner. I have downloaded it and compared it to some GUE Deco Planner profiles as well as Z Planner profiles. It is comparable to Deco Planner (a bit less conservative) and much less conservative than Z Planner. The best part is that it's free, but the model was developed by Younte, Maiken, and Baker -- these guys know their stuff. I would suggest that anyone into this type of stuff check it out.

http://www.coastnet.com/~powercheck/...r/vpln_102.exe

Take care.

Mike

PS. Make sure you know what the heck you're doing before using these type of tables, eh!

[blacknet]

Hello,

Thanks for the info. I'll check it out. BTW for the record I find that deco planner is grosly inaccurate and in some cases down right wrong. Perhaps it's the paramaters i'm using.

Ed

[Lost Yooper]

Greetings Ed,

Most programs are way too conservative. I don't own Deco Planner, but I have a few tables from it. I know Z Planner is WAAYY too conservative. This one (V Planner) is much less conservative. I like it so far. The problem with all of these is they don't keep you at 70' long enough on 50%. One to two minutes isn't long enough to do much good. We always stay about 5mins at 70' as a safety factor (i.e. getting decompressed earlier) in case we have surface prematurely.

Mike

[blacknet]

Hello,

Perhaps we just found something to agree on! I personaly find that GAP is the better one, for me, to use. It seems to run neck to neck with most of the usn tables (cept for acellerated deco w/ o2 and extended range)

Also with GAP I really hate the report system and love the interface. I dislike the interface with decoplanner and departure seems very good so far.

Ed

[Lost Yooper]

I haven't played with GAP either, but I have heard good things about it. Irvine will even give a less-than-reluctant nod to GAP, as he was part of the guinnea pig process with it. With Deco Planner, you have to reduce the conservatism factor bunch, I guess. With this one (V Planner), I have the factor on Nominal (least conservative). We throw in our own safety factors as the dive requires.

If you get a chance, I'd like to see a side by side comparison of GAP and V Planner (say 150' 45mins, 21/35, 50% & O2 deco). Just for curiosity.

Mike

[blacknet]

Hello,

Before I post the info I would like to say if your reading this and plan to dive this profile then KNOW WHAT YOUR DOING! Do *NOT* rely on something you read off the internet to substitute training and experience!

With that said here's the info

Assuming you switch to 100% at 19
stop ft/ min/mix
40/4/50%
30/6/50%
20/11/50%
10/14/100%

With vplanner I get this

Stop at 80ft 2:00 (48) on Trimix 21.0/35.0, 0.72 ppO2, 30ft END
Stop at 70ft 2:00 (50) on Nitrox 50.0, 1.56 ppO2, 32ft END
Stop at 60ft 2:00 (52) on Nitrox 50.0, 1.41 ppO2, 26ft END
Stop at 50ft 2:00 (54) on Nitrox 50.0, 1.26 ppO2, 20ft END
Stop at 40ft 4:00 (58) on Nitrox 50.0, 1.11 ppO2, 13ft END
Stop at 30ft 5:00 (63) on Nitrox 50.0, 0.95 ppO2, 7ft END
Stop at 20ft 9:00 (72) on Nitrox 50.0, 0.80 ppO2, 1ft END
Stop at 10ft 10:00 (82) on Oxygen, 1.30 ppO2, 0ft END


This looks like some computations for deep stops factored in. With GAP I have that turned off and no conservatism. Vplanner appears to have some factored in by default and not user setable.

Now with GAP's deep stops and conservatism turned on I get this

stop ft/ min/mix
100/1/mix
90/1/mix
80/2/mix
70/2/50%
60/3/50%
50/4/50%
40/6/50%
30/9/50%
20/16/50%
10/23/100%

Now the USN tables states (for air)
12/23/51 (all air)
w/ o2
40'/5
30'/7
33 mins at 40' on o2 (chamber)

With this in mind I think gap wins hands down.


Ed

[Lost Yooper]

Hey Ed,

How about the GAP profile with no conservatism using deep stops? Your V Planner profile is pretty close to what mine spits out, but I have a switch at 20'.

Mike

[blacknet]

Hello,

GAP with conservatism OFF,deep stops ON, 50/50 and 100%

foot/time/mix
50/1/50%
40/5/50%
30/6/50%
20/12/50%
10/15/100%

BTW it's a freebe

http://www.gap-software.com/

Ed

[blacknet]

Hello,

and forcing GAP to do 100% at 20' w/ deep stops I get this

feet/time/mix
50/1/50%
40/5/50%
30/6/50%
20/9/100%
10/14/100%

With conservatism of .2/.7

feet/time/mix
100/1/mix
90/1/mix
80/3/mix
70/2/50%
60/3/50%
50/4/50%
40/6/50%
30/9/50%
20/12/100%
10/21/100%

[Lost Yooper]

Interesting. V Planner will get you out in 36mins and GAP in 39min -- things being as equal as possible. I'll take that. I like the deeper stops V-planner is doing, especially when using helium.

Mike

PS. We posted about the same time. I was referring to your previous post with 10' stops and no conservation.