Improving Ascent/ Safety Stop Practices

[RTodd]

Ummmm. Reality is exactly opposite of what you said.

V-planner is a dual phase, aka "bubble" model. GUE's Decoplanner is classic Buhlman, aka "bend and mend", with the addition of the gradient factors as an attempt to get the same results as RGBM / VPM bubble models..

Try reading what I wrote a little slower.

 

[Rick Inman]

I've never had that kind of problem on a charter boat Rick.

The capt./Owner of THIS CHARTER (PNW) says during the briefing, less than 500PSI back on the boat and your diving is done.
This CHARTER in hawaii pulled a guy off the anchor line with 300PSI while he was waiting for his wife.
However, Pug, one look at you and they are probably afraid to say anything!

 

[Uncle Pug]

Two excellent examples of dive ops to avoid... thanks, Rick.

And you are probably right in one regard... how you deport yourself on the boat probably does have some bearing on how they treat you.

 

[Diver0001]

The capt./Owner of THIS CHARTER (PNW) says during the briefing, less than 500PSI back on the boat and your diving is done.
This CHARTER in hawaii pulled a guy off the anchor line with 300PSI while he was waiting for his wife.
However, Pug, one look at you and they are probably afraid to say anything!

I've seen it in Turkey too. I don't know if it was a regulation or not but they were recording finishing pressure from all the divers.

I was probably the most consistent diver they've ever had..... I just said "50 bar" every time I got out of the water and it was duly recorded.....

R..

 

[lamont]

I think that a better practice for NDL rec diving might be to simply halt your ascent every 10 fsw up to 30 ft, do a 1 min @ 30, 1 min @ 20, 3 min @ 10, and then pack on as much extra padding in the 5-20 fsw range as you deem necessary based on how agressive the dive was, what your SI was, how much repetitive diving you've been doing, and how long you just feel like hanging out...

GUE is now suggesting doing 1 min stops from 65% of ATA / 50% of depth for minimal deco all the way to the surface. I'm not sure how much this is based on deco principles and how much this is trying to instill good practices in divers who are going to go on to technical training...

 

[cmalinowski]

Again, you have your reasons for the hit (As best as we know), plus, it didn't require a chamber, making it at least an extremely mild one.

Heck, I think we all have had one of those!!!

OK, I have to ask this and I am not sure where to do it; so sorry for the threadjacking:
can you have a mild hit that you "get over" eventually? I had thought so before I actually took up diving. I figured that the nitrogen has to eventually dissolve. Then, when taught, I felt that there was no such thing as a mild hit.

I also thought, after my teachings, that it just gets progressively worse. Which means that since I am still in about the same condition as when I got back on the boat two weeks ago, I am just dandy.

I ask because I get concerned. I have some disk issues in my neck that cause my fingers to tingle in general, so that's not going to be an idicator.

Any pointers on where to go to find out more about this would be helpful.

Thanks,

 

[Rick Inman]

OK, I have to ask this and I am not sure where to do it; so sorry for the threadjacking:
can you have a mild hit that you "get over" eventually? I had thought so before I actually took up diving. I figured that the nitrogen has to eventually dissolve. Then, when taught, I felt that there was no such thing as a mild hit.

I also thought, after my teachings, that it just gets progressively worse. Which means that since I am still in about the same condition as when I got back on the boat two weeks ago, I am just dandy.

I ask because I get concerned. I have some disk issues in my neck that cause my fingers to tingle in general, so that's not going to be an idicator.

Any pointers on where to go to find out more about this would be helpful.

Thanks,

Check out the 5 Minute Neurological Exam HERE.

 

[pt40fathoms]

Ummmm. Reality is exactly opposite of what you said.

V-planner is a dual phase, aka "bubble" model. GUE's Decoplanner is classic Buhlman, aka "bend and mend", with the addition of the gradient factors as an attempt to get the same results as RGBM / VPM bubble models..

This may sound like a silly question, but when did V-planner change from classic Buhlman? Is the information I have wrong, in that both the Nitek HE dive computer and V-Planner both use the same models and will create similar if not the same deco schedules? These models I though were 16 compartment Buhlman (ZL-L16C).

Unless of course ZH-L16C is not what you are refering to as "classic Buhlman", as I have always considered it too be.


:06:

 

[Charlie99]

This may sound like a silly question, but when did V-planner change from classic Buhlman? :

http://www.hhssoftware.com/v-planner/index.html is the one I assume the other poster was talking about when referring to V-planner. Also can be accessed via www.v-planner.com . It uses the variable permeability model, which is a dual phase model developed by Yount and Hoffman.
The V-planner author, Ross Hemingway is here ocassionally, and also on thedecostop. Before adapting the VPM code to make Vplanner, he did put out the Buhlman based Zplanner.

There are quite a few Buhlman or neoHaldanian programs out there ..... the older GAP program, DDPLAN, Dplanner, Decoplanner, Zplanner and a host of others, so I can't eliminate the possibility that there is a Buhlman program called V-planner, but that's not what comes to mind with most people. To the best of my knowledge, Vplanner has never been anything other than VPM based, although it has changed from the original VPM model to the VPM-B model.

Charlie

p.s. The DiveRite sells the Voyager deco software, perhaps that is the one that you are thinking about matching up with the ZHL-16 based Nitek.

 

[Charlie99]

On the V-planner site, Ross Hemingway has an interesting page titled Some common practices, myths and mistakes on decompression.

It has some interesting comments. The sections on "slow ascent off the bottom", "adding deep stops?", and "First stop = 80% ATA of depth ? " are particularly relevant to this thread.

Charlie Allen