[Dominic]

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May be of interest to some people..
Despite getting Nitrox-certified some time ago, I've only just gotten around to getting myself some deco planning software. (Largely because I got a Palm for Xmas)
So I've just been having a play around with DecoWeenie to get to know how it works.
I wanted to see what kind of difference accelerated deco would have on deco times. So I ran through the same dive (30 meters for 40 minutes) with the following gases:
1 - Air
2 - Air + 80% Nitrox (Yay BSAC)
3 - Air + Pure Oxygen
4 - Air + 50% + 100%
5 - Air + 50% + 80%
6 - Nitrox 36%
7 - Nitrox 36 + 50% +100%

And the resulting deco times with the default Gradient Factor settings were:
1: 1min @ 15, 1min @ 12, 5min @ 9 and 35min @6: Total stop time = 42mins
2: 1min @ 15, 1min @ 12, 2min @ 9 and 12min @6: Total stop time = 16mins
3: 1min @ 15, 1min @ 12, 5min @ 9 and 10min @6: Total stop time = 17mins
4: 1min @ 15, 1min @ 12, 2min @ 9 and 10min @6: Total stop time = 14mins
5: 1min @ 15, 1min @ 12, 2min @ 9 and 10min @6: Total stop time = 14mins
6: 0min @ 15, 0min @ 12, 1min @ 9 and 7mins @6: Total stop time = 8mins
7: 0min @ 15, 0min @ 12, 1min @ 9 and 3mins @6: Total stop time = 4mins

So if you were ever in any doubt about how much diving has progressed with this newfangled approach to decompression, there's your answer:
Just using air, more deco time than down time.
Just using Nitrox, less than ten minutes hanging.
Using full-on accelerated deco, your total deco time is barely longer than your safety stop on a no-deco dive!

 

[Jay]

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You got any PC based deco software I could play around with?

 

[Dominic]

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Got Zplanner, which I never really got on with, but mainly because I didn't take the time to learn it..

http://www.v-planner.com/ has the latest version, I believe. It's free (Or it was when I got it)

 

[Tim Ingmire]

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Thats a very interesting comparison.  Sure shows the benefit of Nitrox.  

I was with Mark Emery at Stoney before xmas and he showed me this software and I thought it was excellent, one for the shopping list.

 

[Tim Ingmire]

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Hey Heads,  when we were with Andy H on the 'Trox course he said that he a cd with some deco software on it that he could copy for anybody interested.  He did also say that you would have to sit down with him and learn to use the stuff properly as well - sounds good to me.

 

[Dominic]

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It could also be used to show the 'advantage' of using BSAC tables - I just looked up the deco requirements the '88s would make for the same dive on air.

1 min at 9 and 9 mins at 6: Total 10mins deco.

Ouch.

 

[Tim Ingmire]

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Dom,

you should post this on the BSAC site and see what response you get.

And I thought the '88 tables were supposed to be fairly conservative.

 

[Dominic]

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Thanks, but I'm not in the mood to be flamed today

When it comes to deco planning in BSAC, one conversation I once had will always stand out most:
Me: "I wonder why he (Bennet on his record-breaking dive attempt) is wearing two computers. He'd have planned that dive on tables, why bother with multiple computers?"
Fellow BSAC club member: "No, tables only go down to 50 meters or so, you need computers on deep dives like that."
BSAC divers are great, they keep bang up to date with diving technology

(I'M a BSAC diver by the way, before anyone has a go)

But you have to bear in mind the fact that BSAC tables work in a different way to Buhlmann, in that they include the surface interval as part of the off-gassing phase. Which means that you get out of the water quicker but the time you spend above water has to be considered as an integral part of your decompression.
I believe it was developed like that because high priority was given to getting people out of the water ASAP - it was reckoned you were better off offgassing on the boat than in the water.

 

[Dominic]

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Should also have mentioned GAP - also free, from http://www.gap-software.com
Runs on a PC, and does all the ZHL16 + gradient factors stuff.
I have to say, I found all the PC-based deco software hard going until I had a play around with DW. I now understand it well enough to make it do what I want.
So I recommend giving DW a go, even if it means downloading a PALM emulator first

 

[Mark]

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Hi,

the software that I showed Tim was DPlan (from GUE). I also use JPlan (get it here - www.fly.to/oxford ) which is free and also very good. Very simular results from both progs.

Enjoy

Mark.

 

[Paul Hinchliffe]

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Dom, Im no expert on this kind of thing, but belive the reason JB wears 2 computers on every deep dive is for back up, its ok having the dive plan, but what if something gos wrong with the plan, say entanglement for one instance, this would possibly increase the bottom time which would be where the computer would save a bend, if he only had one computer and it failed what happens then? Redundancy is the key to survival at that level of diving as he has proved by never getting a bend. I think it is the norm for deep divers to wear 2 computers, but will stand corrected if Im wrong.

 

[Dominic]

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Having had a look at the profiles generated for 100m+ dives, I've actually come to the conclusion that he took them down because the tables for that kind of dive are exceptionally long.
30 deco stops for 100m is bad enough, but having to look through a list of 100 deco stops would be a major pain in the rear.
Looking at a nice friendly computer screen that just tells you the next depth and how long to spend there would probably be preferable

I think you'll find that most deep divers just carry backup tables as opposed to relying on computers tho. (According to some, they don't even need the extra tables half the time, as they're so used to doing deco they can work it out for themselves)

 

[Paul Hinchliffe]

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yeap good point, but record breaking diving entales taking equipment to depths it has never been to before so its anyones guess if it can stand up to it so you must have some kind of back up, the more the better in my opinion,"looking at nice friendly computer screen" is ok if its still working after going to 300+ mtr! but I have not experienced diving to those depths and definatly never will, so I am hardly in a position to argue, but must admit quite eager to learn.
Getting off that, I have recently been given a deco planning software and can not get the thing to work on my computer which is a bummer as it was the the only program I knew how to work as I used it with my TDI stuff, it was a copy from abroad and he even emailed another copy to me and I cant open that either. Has anyone had any trouble like this and can maybe shed some light on it, or am I simply going to have to buy the real thing? many thanx




(Edited by Paul Hinchliffe at 2:17 pm on Feb. 12, 2003)

 

[Dominic]

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"so you must have some kind of back up, the more the better in my opinion,"looking at nice friendly computer screen" is ok if its still working after going to 300+ mtr!"

Absolutely, but I meant taking the pooters as well as the tables, not instead of..

"but I have not experienced diving to those depths"

None of us have, that's why it was a record

"Has anyone had any trouble like this and can maybe shed some light on it, or am I simply going to have to buy the real thing?"

What was the software, and what's the computer?

 

[Paul Hinchliffe]

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k m8 nuff said.
got it going now my pc was missing a few files thanx anyway,


(Edited by Paul Hinchliffe at 2:26 pm on Feb. 12, 2003)

 

[And]

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Hi

Whats the error message?

Might be able to help.

Kindest Regards

WL

PS I've just started using the new Vplanner which is free and pretty good. Got the new RGBM model dontcha know.

 

[Paul Hinchliffe]

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Think Ive (well not me) cracked it, it had been copied from a hard drive not the disc and my mate has had to collect things for it from the internet, which makes very little sense to me, but I will find out tomorrow if its OK, where do you find the vplanner, on line? many thanx

 

[Jay]

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Just emailed it to you.

 

[Phil Ennis]

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Jay,
Do you know of any Deco Planners for the Apple Mac. I have searched but have been told I need some PC emulator software, dont want to go that route as the Mac is running very sweet and I want it to stay that way.