I have read much if not all of what GI has to say about decompression. Other than the fact that I think he is a little vague on how to determin the length of the shallow stops, alot of it seems to make sense and I'm sure it works for the dives they are doing. However, the WKPP is not the first group to develope "rule of thumb" decompression procedures. In fact, there have been many, going all the way back to the very beginning of scuba. One of the problems with them is that what works for one group of divers doing one type of dive has at times bent and killed other divers doing other types of dives.
I also realize that no model that we now have accurately predicts what is heppening in a divers body. However, the model is an attempt to model a system. Once we show that the predictions of the model are reliable under the range of conditions we are interested in we have something usable. Some of the models in use have had fairly extensive testing (using some sample of the population over some range of profiles)and have been used by thousands of divers over tens of thousands of dives in just about any environment and profile imaginable.
My concern is this, When a "rule of thumb" model dramatically differs from a model with significant testing and use behind it there is a big question left that isn't so easy to answer. As far as I know the WKPP methods, in many ways, don't match RGBM, VPM beulmen or any other. I'm not talking about little things like lengthiening a switch stop or shortening the stop before a gas switch. I'm talking about big things like assuming your clean and ready to go 30 minutes after a dive and no allowances need to be made for a repetative dive. What about repetative dives over multiple days. I can't help but think there are many variations in profiles and divers under which these methods and assumptions have not been tested, at least not to a statistically significant degree. Keep in mind that when you say it is proven over thousands of dives, if indeed it has been that many, thats nothing. Now, if these divers are too much alike and the dives are too much alike then the number of dives is totally irrelevant because it is then more like testing one diver on one profile. Other models have been proven over many times that over a wider range of profiles and a wider range of divers.
The number of different profiles I have decompressed from and the number of methods I have tested doesn't qualify me to say what will work and what won't. I am certainly interested in hearing what results other divers have had with the WKPP methods and under what conditions. To believe that the WKPP found something that will work better under all conditions than the many scientists who have worked on this problem over the last couple hundred years and missed with all their testing defies common sense. A perfect example of my concern is the assertion that previous dives can be ignored. this is in contradiction to every model or theory out there as far as I know. How did BRW and Baker miss that one? Maybe it is true but it defies everything we think we know about the behavior of gasses in tissue.
May I ask what your personal experience is and to what extent you have tested these methods and under what conditions?
