Padi Dive Wheel ?

[pt40fathoms]

bakpakka once bubbled...
Guess we've paid for our PADI accreditation, gotta fork out more for safety I guess. I reckon an RDP is such an important "widget" that it should be made available to all who have already paid their dues in order to become a diver.

You did pay for one when you took your open water course through PADI. If you took the course with another agency, then you should be using whatever aid they included with their course.

[/i]It's rather like patenting the cure to AIDS. All mankind should donate to the development of such a cure. But hey, of course a company with financial focus should take it up, patent it and charge exorbitant fees, shouldn't they. Now, that's rather self-centred, eh?

Ahh, "all mankind should donate", do you mean MONEY?

So on that same line of thinking, 'all divers should donate to the development of the PADI RDP'. Therefore all divers would have unhindered access to the RDP. But wait, what about non-divers who have not donated?

Is that what you would like to see?

Well of course my two cents about the RDP ain't gonna make it available for free, but copyrighting it? Perhaps selling the genuine stuff is fine, but prohibiting others to copy it for safety / life saving?

Copyrighting is a tool that was put in place to help protect intellectual knowledge as well as printed material. Without it we would never see great works of literature, enjoy good music, or see advancements in knowledge on the scale we see today. Like it or not, people want to be rewarded for the efforts they put out. To deny this reward is not only wrong, but has a very disastrous effect on both progress and society on a whole. One need only look to countries that have tried to follow a path that opposes this view, and you will see a country that is listed as "third world" and in constant need of aid from countries that do reward and protect its citizens. Making copies of copyrighted material is a crime, and is legitimately so. It is theft plain and simple.

 

[Charlie99]

pt40fathoms once bubbled...
Copyrighting is a tool that was put in place to help protect intellectual knowledge as well as printed material. Without it we would never see great works of literature, enjoy good music, or see advancements in knowledge on the scale we see today. Like it or not, people want to be rewarded for the efforts they put out. To deny this reward is not only wrong, but has a very disastrous effect on both progress and society on a whole.

I notice you are from Canada. Thanks for supporting the development of the DCIEM tables. Too bad they are copyrighted, and not available over the internet, as are the U.S. Navy / NOAA tables.

I do agree with you about privately sponsored research being protected. I doubt we will be able to get the RGBM NAUI tables for free, but the work on them needs to be supported somehow.

 

[Dr Deco]

Dear Readers:

What Is The Recreational Dive Planner?

Ray Rogers, DDS, developed the RDP with the purpose of creating dive table specifically for recreational divers. To this end, the table would appear with smaller increments than US Navy decompression tables and would have the repetitive groups based on the 60-minute halftime tissue. The first allows a finer differentiation such that a diver is not heavily penalized for going from 60 to 62 feet. Instead of rounding to the 70-foot depth, the diver could now round up to 65 feet.

The shorter elimination halftime (sixty minutes) was based on the idea that long compartments were not load with SCUBA gear. The long washout compartment was made for hardhat, surface supplied diving gear and long decompressions. That is not the recreational diver diving method.

In addition, “The Wheel” allowed a diver to perform multilevel dives. It was a nice advance for its time. Because it has been laboratory tested, it is a good standard and the pedigree of many decompression meters trace their origin to this system.

Testing Program

When the calculations were completed, it was decided that a full test program should follow. I was the head of this test program while I was at the Institute of Applied Physiology and Medicine in Seattle, Washington. This was a long and expensive process.

Not only is this virtually the only controlled test program for recreational divers in a multiday scenario, but the results were published for all to read. Two reports were written, the first by me on the Phase I program and the second by Dr Bill Hamilton on the Phase II (multiday program). All of the material is available and can be purchased from DSAT for about $10.

Diver Safety

Dive table are built for diver convenience. It is assumed that all tables are safe. What is being purchased is a format that allows the theoretical tracking of dissolved nitrogen in “compartments” of your body. Knowing this information is akin to having a “road map of the pressures within your body.” Tables do not allow you to dive. God and nature does this. Tables are simply a tool. It is the format of the tool that the table designer sells. The tables are not patented. The format is, however, copyrighted.

Dr Deco :doctor:

Readers, please note the next class in Decompression Physiology :grad:
http://wrigley.usc.edu/hyperbaric/advdeco.htm

 

[DA Aquamaster]

fins wake once bubbled...
I don't agree. Compared with a lot of tables the ("new") RDP is clearly more conservative (e.g. MN90, BSAC 88, US Navy, Bühlmann ZH16). Also, the RDP is generally considered a conservative table all-around. The fact that there are some even more conservative tables/deco programs around is incidental. This is BTW an excellent topic for the Dr Deco section of this board, for many reasons ...

Let me rephrase that, the RDP is more liberal than the other tables currently promoted by rec training agencies such as SSI...and I would not call a US Navy table part of the "current" crop of dive tables.

 

[fins wake]

I've dived with SSI-trained divers from Spain and the UK (and been very impressed by the way! It must be an excellent agency) but I've never seen their tables. Which ones do they use?

and I would not call a US Navy table part of the "current" crop of dive tables

You'd be surprised! A lot of tables, particularly in the technical domain, are still based on this one.

Dr Deco has already chipped in (as I hoped he would) with more great info on the RDP. (And again, some info which was news to me despite following Dr Powell's section carefully.)

Personally, using the RDP as "a check" on other tables and on my computer when fun diving, I find it excellent. I personally do not fear that it's too liberal by any stretch of the imagination. Incidentally, the BSAC 88 and MN90 are used by recreational training agencies as well, albeit European ones (UK and French national federations, respectively).

It is assumed that all tables are safe.

That's not to say there are tables which may be more popular with some divers than others. Because PADI is by far the biggest diver training agency in the world, the RDP could be considered one of the recreational standards. But how many people actually know how to use the RDP properly, and know all of the small exceptional rules? The XYZ or cold-water rules, for example? I know lots of divers who even don't understand how to arrive at their end-of-2nd-dive groups properly ...

The last thing I would call it is safer particlarly on multiple dives over multiple days.

Even PADI warns that the effects of repeated dives over multiple days isn't fully researched. Dr Deco has clearly stated why (it's very expensive and it's difficult to test for all variables). However, this is true for all tables!

The fact that so many people use tables (and their derivatives) on multi-day multi-dive liveaboards yet (generally) do not appear to come down with DCI indicates the relative safety of modern dive tables.

 

[Charlie99]

fins wake replied to DA Aquamaster...
You'd be surprised! A lot of tables, particularly in the technical domain, are still based on this one. [US Navy]

SSI is based on the doppler adjusted USN tables. NAUI and PDIC tables are also variants of USN tables. All three have reduced NDLs, but use the USN pressure groups and repetitive dive calculations.

Repetitive dive calculations on these tables are all based upon the 120 minute halftime compartment. This is rarely the controlling compartment in recreational diving, and this results in much less allowable bottom time for repetitive dives than allowed on the PADI RDP. The 60 minute compartment is the controlling one for PADI RDP, except for long, shallow dives that invoke the WXYZ rules.

SSI tables, and many others can be found at http://www.vanwaasen.de/TABLES/DIVETABLES.HTML
and
http://www.flash.net/~table/table/p0000065.htm

 

[Ron Brandt]

I wish they would just get rid of the wheel.Who actually carrys it with them on every dive?

Ron

 

[KrisB]

Charlie99 once bubbled...
I notice you are from Canada. Thanks for supporting the development of the DCIEM tables. Too bad they are copyrighted, and not available over the internet, as are the U.S. Navy / NOAA tables.

I do agree with you about privately sponsored research being protected. I doubt we will be able to get the RGBM NAUI tables for free, but the work on them needs to be supported somehow.

This whole discussion shows a lack of understanding of the term 'copyright.'

Copyright merely attempts to attribute the author to the work -- it is copyright that requires an individual to cite their sources in an academic (like an essay, term paper, thesis, dissertation, etc.) or other work. In fact, it is also the copyright that requires an author to cite his own work if used at a later date.

Copyright is not necessarily attached to compensation. This is attached to the "rights" which the copyright owner places on his work. A copyright owner may, at his/her discretion, place his/her work into the "public domain" -- free use and distribution with or without profit. This is rare.

A copyright owner may also, at his/her discretion, place his/her work with a different sort of license -- we've all seen "free for non-profit use" on items, whether it be a piece of software, music or book. This usually means that you can copy it and distribute it, as long as you are not profitting from it.

For what the PADI table costs to purchase, it is likely that they could just as easily place a "not-for-profit" license on the table, as they are likely just recovering the manufacturing costs... it isn't cheap to print on plastic, you know!

FWIW, depending on the license, it could be violated by the following sentence: "after a thirty minute dive at fourty-two feet, you are an 'I' group diver." Be thankful that PADI doesn't police it that much!

Also, to Charlie99: don't discriminate based on nationality, please. We could just as easily make some comments here about the money-hungry capitalist attitude that seems to prevail south of the 49th parallel.

 

[Charlie99]

KrisB once bubbled...
This whole discussion shows a lack of understanding of the term 'copyright.'

A copyright owner may, at his/her discretion, place his/her work into the "public domain" -- free use and distribution with or without profit. This is rare.


Also, to Charlie99: don't discriminate based on nationality, please. We could just as easily make some comments here about the money-hungry capitalist attitude that seems to prevail south of the 49th parallel.

My point was that the publicly funded USN and NOAA tables are in the public domain. The publicly funded DCIEM work is not, and it appears the Canadian government or their agent actively seek out instances of DCIEM tables being on the internet and have them removed.

DCIEM tables are interesting because they are based on a serial tissue model, rather than the more common parallel tissue model. Repetitive dives calculations are by a multiplicative factor, not additive residual nitrogen numbers.

Sorry about my apparent lack of knowledge on intellectual property.

Actually, I'm one of those money-hungry capitalists. Having just received my 15th U.S. patent in May, I do believe in private intellectual property rights.

 

[KrisB]

Charlie99 once bubbled...
My point was that the publicly funded USN and NOAA tables are in the public domain. The publicly funded DCIEM work is not, and it appears the Canadian government or their agent actively seek out instances of DCIEM tables being on the internet and have them removed.

DCIEM tables are interesting because they are based on a serial tissue model, rather than the more common parallel tissue model. Repetitive dives calculations are by a multiplicative factor, not additive residual nitrogen numbers.

Are they available at all? (for purchase or otherwise) If so, perhaps what the copyright owner (whoever that may be) is doing is trying to maintain control over the *accurate* reproduction. There are many cases where the only reason to hold something that close is to ensure that when a person make a copy, it is an accurate and reliable facsimile.

Actually, I'm one of those money-hungry capitalists. Having just received my 15th U.S. patent in May, I do believe in private intellectual property rights.

Well, that doesn't necessarily make you a money-hungry capitalist. A better example of a money-hungry capitalist would be someone who takes a $0.99 bar of soap, mixes it with water, then markets it in a lotion form as "weight-loss lotion" for $25.00 on late-night infomercials. Of course, they sue anyone who does the same. While extreme, I don't think this is too far from the truth in some cases!